I 

COMPLETE  REPORT 

of 

J.  J.  de  KINDER 


On  the 

Vosmaer  System  of  Producing 
Ozone  for  the  Purification  of 
Water  and  other  purposes. 


Owned  by 

The  United 

Water  Improvement  Company 

PENNSYLVANIA  BUILDING,  PHILADELPHIA 


Philadelphia 

George  H  Buchanan  Company 
1905 


(o?.%.\G 

Yvvi  c 


i 


Digitized  by  the  Internet  Archive 
in  2018  with  funding  from 

University  of  Illinois  Urbana-Champaign  Alternates 


https://archive.org/details/completereportofOOdeki 


UY<Vv\V£.Vcv\VR, 


Report  of  Investigations  and  Result  of  same 
made  at  Nieuwersluis,  Holland,  of  Water 
Sterilization  by  Ozone 


System,  A.  VOSMAER 


DESCRIPTION  OF  PLANT: 

The  plant  consists  of  : 

(a)  A  steam  boiler ; 

(b)  Air  drying  tank ; 

(c)  Kronke  rough  filter: 

(d)  Standpipe; 

(e)  Ozonizer; 

(f)  Water-pump; 

(g)  Airpump; 

(h)  Alternating  current  generator; 

(f)  Step-up  transformer  with  switchboard  and  a  spe¬ 
cial  condenser,  with  all  necessary  piping  and  wiring,  the 
whole  covering  a  ground  space  of  about  20  x  40  feet  inde¬ 
pendent  of  the  adjoining  laboratory,  which  covers  a  space  of 
about  10x15  feet- 


» 


4 


CAPACITY: 

The  water  ozonizing  capacity  of  the  plant  is  equal  to  20 
cubic  meters  per  hour,  or,  in  round  numbers,  5300  gallons. 


LOCATION: 

The  plant  is  located  at  Nieuwersluis,  on  the  River  Vecht, 
between  the  cities  of  Amsterdam  and  Utrecht. 

The  “Vecht”  is  a  small  stream  which  is  fed  from  the 
River  Rhine  below,  and  moves  either  slowly  towards  the 
Zuyder  Zee,  or  is  checked  entirely  when  the  tide  in  the 
Zuyder  Zee  is  high.  It  is  one  of  the  most  polluted  waters 
in  Holland,  inasmuch  as  the  city  of  Utrecht,  and  all  of  the 
great  many  smaller  towns  and  villages  along  its  borders,  as 
well  as  numerous  factories,  laundries,  etc.,  use  it  as  a  common 
drain;  besides  a  very  large  surface  of  Polder  land  empties  its 
waters  into  it,  and,  hence  Vecht  water  contains  a  high 
percentage  of  soluble  organic  matter  at  all  times,  and  a 
remarkably  high  percentage  after  heavy  rains. 


GENERAL  OPERATION: 

The  water  to  be  ozonized  is  conveyed  by  means  of  a 
pump  from  the  Vecht  to  a  Kronke  rough  filter,  and  from 
there  to  the  top  of  a  standpipe,  having  a  diameter  of  15 
inches  and  a  height  of  35  feet,  down  which  standpipe  it  flows 
on  its  way  to  the  receiving  reservoir  located  outside  of  the 
building. 

Air  is  drawn  by  means  of  an  airpump  from  an  iron 
tank  in  which  are  compartments  or  shelves  upon  which  chlo¬ 
ride  of  calcium  has  been  charged  and  issues  from  the  tank  in 
a  dry  state,  the  chloride  of  calcium  having  absorbed  the 
moisture  which  it  contained  before  entering  the  tank. 

On  its  way  to  the  suction  side  of  the  pump  the  air 
passes  through  the  ozonizer,  an  apparatus  consisting  of  a 


J 


number  of  light  copper  tubes,  each  about  three  (3)  inches 
in  diameter  and  sixteen  (16)  feet  in  length,  the  tubes  bekig 
supported  at  either  end  in  headers  (in  the  manner  of  an 
ordinary  closed  feed  water  heater),  the  air  discharge  pipe 
from  the  drying  tank  connecting  with  the  header  at  one  end 
of  the  ozonizer,  and  the  air  suction  pipe  to  the  airpump  with 
the  opposite  header  of  the  ozonizer.  The  pump  compresses 
the  air  to  slightly  above  atmospheric  pressure  and  delivers  it 
in  the  bottom  of  the  standpipe  already  referred  to  in  which  it 
ascends,  distributing  itself  in  minute  globules  through  the 
descending  water. 

In  the  ozonizer,  the  air  in  passing  through  the  tubes  is 
ozonized  by  means  of  a  silent  electric  discharge. 

An  ordinary  generator  delivers  its  alternating  current 
to  a  switchboard,  from  whence  it  goes  to  a  step-up  trans¬ 
former  and  from  here  to  the  dischargers  which  are  located  in 
the  tubes. 

There  is  nothing  out  of  the  ordinary  about  the  trans¬ 
former  or  any  other  part  of  the  electrical  apparatus,  with 
the  exception  of  the  condenser  (A.  Vosmaer  patent),  which 
is  of  special  design.  From  one  and  one-half  to  two  grams 
of  ozone  (03)  per  cubic  meter  of  water  pumped  are  used, 
and  the  electrical  energy  required  to  produce  one  gram  of 
ozone  is  about  60  watts  (one  kilowatt  hour  producing  about 
15  grams  of  ozone),  and  the  quantity  of  ozonized  air  re¬ 
quired  for  the  ozonizing  of  the  water  is  in  proportion  of 
about  one  and  eight-tenths  volumes  of  atmospheric  air  to 
one  volume  of  water. 

Upon  my  arrival  at  Nieuwersluis  on  February  4,  1904, 
I  placed  myself  in  communication  with  the  inventor,  Mr.  A. 
Vosmaer,  and  with  Dr.  A.  Lebret,  the  well-known  bacteri¬ 
ologist  in  charge  of  the  bacteriological  department  of  tiie 
ozone  company  (Ozone-Maatchappy,  System,  A.  Vosmaer)  , 
and  preparations  were  at  once  made  for  examining  every 
detail  of  the  plant,  and  for  making  tests  under  different  con- 


6 


ditions  of  quantities  and  qualities  of  water  supply,  etc.,  the 
results  of  which  are  shown  in  the  following  table : 


re 


oj  tj  i—  o  mo  oo 


CP 

M 


o 

►t 

QTQ 

P5 


o 

n> 


M 

< 

Cl. 

cd 


m 


n 

c 

cr 


—  •  —  o 
°  "  3 

3  ^ 

P  — 

On 

ft> 

“I 

VI 

3 
O 


ft) 

“  a 

On  — j 

o  ro 
C  kQ 
cr  c 
o  EL 


!  + 


CZ- 

2!  rt  to 

»>  on 

p  rc  ° 

_  5  orq 

c  ^  p 


o 

c 

3 

p 

ir. 

r~t- 

o 

o 


o 


fD 

p 

7T“ 

a> 


o 

p 

ft 


03 


00 

O 

o 

5« 

P 


ft 


O 

c 


p^  pH 

t-n  O  *'■*4  *<t  Lri  Ln 

Ln  L n 

Wafer  per  Hour 
in  Cu.  Meters 

P-  PH  PH  PH  PH  P- 

Os'  QV  Qn  Q\  Qn  Q\ 

oc  GO  00  oc  00  00 

Ozonized  Air  per 
Hour  in  Cubic 
M  eters. 

PH  PH  PH  PH  PH  PH 

O'  O'  O'  O'  O'' 

Ozone  in  Grants 
per  Cu.  Meters 

to  to  to  to  to  to 

O  O'  O'  O'  O'  O' 

00  00  00  00  00  00 

00  00  00  00  oc  00 

Total  Ozone  in 
Grams 

-H  to  O-.  Oj  Cn  On 

— I  01  Oj  Cu 

M3  C  00  00  00  00 

Ozone  per  Cubic 
Meter  of  Water 
in  Grams 

00  00  00  00  00  00 

0  0  0  0  0  0 
000000 

Electric  Energy 
in  Watts 

4L 

01  oj 

O'  -0 

OC 

to 

O'  O 

CCOj 

Ln 

^*3 

0 

O 

0 

4^  Oj 

P  pc 

0 

O 

0 

O 

O 

0 

«  i. 

0 

O 

0 

O 

O 

0 

c n 

O' 

Oj 

00 

00 

PH 

O 

PH 

1  w  3 

?T 

-p  I- 

H  Ul  h  K)  M 


On 


w  O  OJ 


C/3 
P 
N  3 
T3_ 
ft 

C/2 

P 

oj  3 
fT 


§33 

fT  U 
£3  f*-  <T> 

S  2  ^ 

ro  *  n 

O  P 
°  pp  — 

r.2  p 

•  O 

H  a 
rr  ^ 

« p' 
rt-c 
03 
y  rs 


o 

‘  ft 


hj  l-H  >-< 

-P  CC  'O 
Oj  MO  ■- 


to  1— 1  1— 1 

w  -p  -P 

CO  tJ  W 
on 


«  M  K) 

O  -P  On 

01  I 


tO 

(O 

ON 


OJ 


to 

Oj 


to 


2  CC 

N  S' 
»  3 

cr.  ft 


o  3 

C3 
X  orq 

5:2 


-•Orq 

O 


o 

N 

o 


> 


.  QTQ 

p 

z  3 


P  <T> 

zr.^ 

c 


F 

3'?  = 


Per  Cent,  of  Re¬ 
duction 


M 

x 

ft 

P-*  • 

3 

r» 

3 

W 

O 

p 


ft 

& 

O 

c 

p 


3* 

ft 


ft 

C 

S 

ft 

►n 

C/1 

cT 

Ui 


P 

3 

r* 

3 

P— 

r-f 

3* 

JO 

O 

C 

crq 

3* 


ft 

>1 

ft 

CL 

P 

r-t- 

CD 

*-! 


The  mechanical  operation  of  the  plant  was  in  charge  of 
the  regular  engineer,  while  the  bacteriological  observations 
were  in  charge  of  Dr.  Lebret,  samples  of  water  for  bacterio¬ 
logical  tests  and  all  observations  being  taken  in  my  presence. 


/ 

“From  a  paper  read  by  Mr.  Vosmaer  before  the  Society 
of  Hydraulic  Engineers  of  Holland,  convened  at  ’s-Graven- 
hage  on  September  12  and  13,  1903,  on  the  sterilization  of 
water  by  the  use  of  ozone,  a  translation  of  which  follows : 

Translated  from  the  Report  of  the  Fourth  Convention 
of  the  Society  of  Hydraulic  Engineers  of  Holland,  con¬ 
vened  at  ’s-Gravenhage,  on  September  12  and  13,  1902.” 


The  Sterilization  of  Water  by  the  Use  of  Ozone 

BY  A.  VOSMAER. 

Gentlemen — About  two  years  ago  I  had  an  opportunity 
to  discuss  before  you  the  question  of  ozone  production,  but 
at  that  time  I  was  compelled  to  limit  the  discussion  to  the 
question  of  production  only,  not  being  able  then  to  elaborate 
the  subject  of  sterilizing  water  by  ozone,  inasmuch  as  there 
was  not  at  our  laboratory  in  Haarlem  opportunity  to  apply 
it  to  the  purpose  of  sterilizing  water,  and  as  a  matter  of  fact 
the  question  of  the  manufacture  of  ozone  is  and  remains  the 
principal  one,  because  all  speculations  in  regard  to  water 
sterilization  by  ozone  amount  to  nothing  unless  ozone  can 
be  manufactured  on  a  sufficiently  large  scale  to  make  it 
applicable. 

Two  years  ago  I  necessarily  limited  myself  to  the  dis¬ 
cussion  of  other  systems,  saying  little  about  our  own.  (See 
sterilization  of  drinking  water  by  ozone  in  De  Ingenieur , 
organ  of  the  Society  of  Civil  Engineers  of  Holland,  2d  and 
9th  of  September,  1899,  Nos.  35  and  36.)  But  we  are  now 
able  to  consider  our  system,  because  it  has  been  thoroughly 
tested.  It  is  not  my  intention,  therefore,  to  lecture  on  the 
question  of  ozone  sterilization,  inasmuch  as  I  would  have  to 
weary  you  with  repetitions.  No  doubt  the  publications  of 
Siemens  &  Halske  are  known  to  you,  and  you  are,  no  doubt, 
acquainted  with  their  method  of  original  operation  with 
tubular  apparatus.  The  first  publication  of  Dr.  Erlwein  in 


8 


1901  covered  apparatus  with  glass  plates,  while  the  installa¬ 
tion  at  Wiesbaden  in  1902  again  involved  the  original  idea 
from  which  it  is  justifiable  to  conclude  that  the  change  from 
tubular  apparatus  to  plates  was  not  a  lasting  improvement. 

In  the  technical  arrangement  of  our  apparatus  we  have 
aimed,  first  of  all,  to  secure  absolute  reliability  and  extreme 
simplicity,  and  in  this  we  have  completely  succeeded,  al¬ 
though  at  the  expense  of  a  slight  economical  loss  in  quantity 
of  production.  The  apparatus  of  Siemens  &  Halske  pro¬ 
duces  a  larger  quantity  per  unit.  The  production  in  grams 
of  ozone  per  kilowatt  hour  is  greater  than  in  our  system,  but 
whereas  they  attempt  to  secure  reliability  (in  Wiesbaden) 
by  the  application  of  a  number  of  controlling  and  danger 
signals  we  have  secured  absolute  reliability  through  another 
system,  viz :  through  the  absence  of  all  dielectrics. 

In  our  apparatus  there  is  no  mica  or  glass  upon  neither 
of  which  reliance  can  be  placed,  and  our  special  electrical 
arrangement  prevents  absolutely  the  creation  of  the  danger¬ 
ous  arc  discharges.  It  is,  therefore,  a  matter  of  personal 
opinion  whether  it  is  more  advantageous  to  have  absolute 
reliability  with  a  somewhat  more  expensive  apparatus  than 
non-reliability  with  a  somewhat  cheaper  one.  Both  systems, 
therefore,  have  their  advantages  and  disadvantages.  Our 
ozone  apparatus,  which  many  of  you  have  seen  at  work  at 
Schiedam,  has  been  much  simplified  and  been  reduced  to 
one-tenth  of  its  size  for  the  same  production.  The  system, 
however,  has  remained  the  same,  only  the  technical  arrange¬ 
ment  as  now  in  existence  at  Nieuwersluis  is  simplicity  itself, 
but  inasmuch  as  the  apparatus  has  worked  at  Schiedam  and 
at  Nieuwersluis  without  any  interruption  of  the  slightest  kind 
day  in  and  day  out  with  constant  results,  it  is  not  necessary  to 
discuss  the  question  of  reliability  any  further.  We  are  mak¬ 
ing  our  apparatus  for  twenty-four  hours’  work  per  day  and 
guarantee  its  reliability.  The  reason  why  I  emphasize  the 
question  of  reliability  so  strongly  is  because  it  is  just  in  this 
reliability  that  our  strength  lies  and  which  justifies  our  claim 


9 


of  superiority  over  any  other  apparatus  for  which  a  claim 
of  higher  production  per  unit  may  be  made. 

But  I  desire  to  call  your  attention  to  the  subject  of  steri¬ 
lization  of  water,  and  in  particular  to  the  results  which  we 
have  obtained  at  Schiedam  and  Nieuwersluis.  When  the 
C ity  government  of  Schiedam  asked  us  for  figures  for  an 
ozone  installation  and  its  cost  per  cubic  meter  of  water 
treated,  we  requested  permission  to  erect  our  plant  at  Schie¬ 
dam  in  order  that  we  might  have  an  opportunity  to  thor¬ 
oughly  test  it,  inasmuch  as  this  could  not  be  readily  done  at 
Haarlem.  This  request  was  granted  and  in  consequence  we 
were  able  to  operate  the  apparatus  for  two  and  one-half  con¬ 
secutive  years  at  Schiedam.  Following  in  the  footsteps  of 
Tyndall  we  contented  ourselves  during  the  first  half  year 
and  during  part  of  the  second  half  year  by  operating  the 
sterilizer  in  accordance  with  Tyndall’s  system,  viz:  entering' 
the  ozone  into  the  water  in  the  direction  of  the  latter’s  flow. 
The  results  obtained  were  not  satisfactory,  and  although  we 
operated  just  as  Tyndall  did  in  Brussels,  viz:  with  20  cubic 
meters  of  water  per  hour  and  40  liters  of  ozone  of  3J/2 
grams  03  per  cubic  meter  the  bacteriological  results  were 
not  satisfactory.  This  induced  us,  inasmuch  as  our  system 
of  ozone  making  was  the  reverse  of  that  employed  by  Tyn¬ 
dall,  to  reverse  the  operation  of  sterilization  also  and  not  to 
attach  any  value  to  Tyndall’s  publications,  and  from  the 
moment  that  we  introduced  a  sterilizer  on  the  principle  of 
countercurrent  our  success  was  assured.  The  sterilizator  is 
arranged  as  follows  :  (See  accompanying  figure.) 

The  water  enters  at  1  and  passes  out  at  2,  while  the 
ozone  enters  underneath  at  3  and  passes  out  at  4  (or  rather 
the  air  passes  out  at  4)  for  at  that  point  the  ozone  has  com¬ 
pleted  its  work  and  is  again  changed  to  oxygen,  or  what  was 
not  ozone  escapes  into  the  atmosphere.  The  apparatus  works 
continuously  and  entirely  as  countercurrent  apparatus,  which 
is  naturally  the  most  economical:  peculiar  construction 

of  the  lower  part  makes  it  impossible  for  the  water  to  enter 


IO 


A  4 


into  the  ozone  supply, 
and  prevents  the  ozone 
from  passing  out  with 
the  water.  The  first  is 
obtained  by  the  pres¬ 
ence  of  the  perforated 
plate  5.  So  long  as 
there  is  sufficient  pres¬ 
sure  water  cannot  pos¬ 
sibly  pass,  on  the  prin¬ 
ciple  of  the  bottom  of 
a  Bessmer  converter. 
The  second  is  obtained 
by  the  presence  of  the 
perforated  wall  6  and 
the  screen  7.  Our  ster- 
ilizator  sterilizer  has  a 
capacity  of  from  20  to 
30  cubic  meters  per 
hour,  a  diameter  of  30 
centimeters  (12")  and 
a  height  of  a  little  over 
10  meters  (34').  You 
are  all  acquainted  with 
the  fact  that  techni¬ 
cally  counter-current 
apparatus  are  the  most 
economical,  and  that  is 
just  the  case  here.  A 
single  example  is  suffi¬ 
cient  to  prove  this.  Ac¬ 
cording  to  the  reports 
of  Siemens  &  Halske, 
to  whom  further  refer¬ 
ence  will  be  made,  they 
used  for  the  purpose 


of  ozonizing  one  cubic  meter  of  water  -f-  two  and  one- 
half  grains  of  ozone,  whereas  we  hardly  need  one  gram 
because  of  our  perfect  sterilizer.  Ozone  does  not  affect  bac¬ 
teria  by  absorption.  Absorption  apparatus  are,  therefore, 
not  advantageous,  because  there  the  intention  is  to  dis¬ 
tribute  a  maximum  quantity  of  gas  through  a  minimum 
quantity  of  liquid,  while  in  ozonization  a  maximum  quantity 
of  water  must  be  treated  with  a  minimum  quantity  of  ozone. 
The  economical  results  are  there  to  prove  this. 

I  will  now  proceed  to  show  what  results  we  have  ob¬ 
tained  with  our  apparatus.  In  Schiedam  they  had  water 
twice  filtered ;  first,  through  coarse  sand,  and  afterward 
through  dune  sand.  We  were  asked  to  treat  with  ozone  the 
water  that  had  been  filtered  once.  The  purpose  was,  there¬ 
fore,  to  substitute  ozonization  for  the  second  filtration.  The 
first  filtered  water,  which  was  very  good,  contained,  accord¬ 
ing  to  Dr.  ’t  Hoff,  from  200  to  1000  bacteria  per  cubic  centi¬ 
meter,  sometimes  less  than  200.  After  ozonization  the  fol¬ 
lowing  figures  were  obtained. 

Results. 


Date 

2 

3 

4 

5 

7 

8 

9 

io 

1 1 

16 

17 

18 

IO  M. .  .  . 

f 

O 

0 

0 

0 

0 

1 

1 

0 

I 

I 

2 

5 

I 

I 

0 

1 

2 

0 

1 

1 

0 

1 

0 

1 

1 

15  M. .  .  . 

{ 

I 

O 

2 

0 

0 

0 

0 

1 

0 

0 

5 

0 

1 

0 

■j 

a 

l 

2 

I 

"> 

0 

I 

2 

1 

5 

2 

20  M. .  .  . 

( 

2 

2 

0 

1 

2 

0 

0 

1 

0 

4 

2 

2 

t 

2 

0 

0 

0 

1 

4 

4 

0 

0 

4 

1 

1 

In  this  table  of  two  weeks’  run  the  figures  given  represent  the  number  of 
bacteria  left  after  ozonization. 


It  represents  three  series,  viz  :  The  ozonization  of  io  cubic  meters  (-(-  2700 
gallons),  15  cubic  meters  (-)-  4050  gallons),  and  20  cubic  meters  (-j-  5400  gallons) 
water  per  hour,  with  one  and  the  same  amount  of  energy  expended  for  making 
the  ozone,  viz.,  2  kw. 

This  is  a  very  good  result  compared  with  the  table  of 
Siemens  &  Halske,  where  it  is  true  the  number  of  bacteria 
was  larger,  but  where  instead  2f4  grams  of  ozone  were  used 
per  cubic  meter.  We  were  working,  however,  under  more 


favorable  conditions,  inasmuch  as  the  water  had  been 
once  filtered,  while  Siemens  &  Halske  worked  with  rough 
filtered  water.  In  our  case,  therefore,  because  the  ozonization 
was  supplementary  to  that  of  filtration  we  obtained  better 
water,  but  at  a  greater  expense.  We  desired,  however,  to 
apply  the  ozonization  just  as  Siemens  &  Halske  did — as  a 
substitute  for  filtration — and  decided,  therefore,  to  transfer 
the  installation  to  Nieuwersluis,  because  the  water  from  the 
Vecht  is  of  worse  quality  than  that  of  the  Maas.  Besides, 
this  Vecht  water  is  not  filtered  (so  called)  but  merely  rough 
filtered  by  a  plain  mechanical  filter  (system,  Kronke). 
Whereas  in  an  ordinary  filter  the  speed  of  filtration  is  some¬ 
thing  like  ioo  millimeters  per  hour  (4'')  in  this  case,  viz: 
with  the  Kronke  rough  filter  the  speed  was  4000  (40")  milli¬ 
meters  per  hour.  When  the  filter  has  worked  for  one  day  it  is 
stopped  and  the  current  reversed,  while  the  drum  is  made 
to  revolve,  by  which  operation  the  sand  in  the  drum  is 
cleaned.  There  is,  therefore,  no  question  of  any  biological 
effect  and  it  involves  simply  mechanical  filtration  or  sifting 
of  matter  in  suspension.  That  more  ozone  would  be  re¬ 
quired  for  the  ozonization  of  this  mechanically  filtered  Vecht 
water  than  for  the  Schiedam  water  was  to  be  expected.  We 
limited  ourselves  not  to  10,  15  and  20,  but  to  5,  10  and  15 
cubic  meters  of  water  per  hour  with  the  following  results  : 

Treatment  of  15  Cubic  Meters  (-  4050  Gallons)  per  Hour 


Date 

Serial  Number  of  Experiments 
(9  each  day) 

Average 

Number  of  Bacteria  in 
Raw  Water 

Organic  Matter  in  Solu¬ 
tion  in  Raw  Water  in 

M  illigram  Permanga¬ 
nate  of.  Potassium 

Per  Cent,  of  Reduction 
in  Organic  Matter 

I 

2 

3 

4 

5 

6 

7 

8  9 

Aug. 

4 

3^ 

35 

49 

1 1 

13 

13 

18 

12  21 

23 

6,860  I.  I  I 

26 

1 1 

5 

2  I 

28 

23 

M 

23 

24 

14 

15  19 

20 

4,410  IO.  I 

25 

a 

7 

2  3 

29 

16 

12 

10 

1 1 

15 

14  12 

l6 

4,770  IO.3 

20 

<< 

8 

1 1 

»5 

6 

!3 

6 

IO 

1 1 

14  12 

I  I 

5,59°  io-7 

24 

k  < 

9 

5 

. 

4 

5 

5 

5 

4 

4 

n  5 

5 

4,050  10.8 

20 

Average 

15 

I 


Treatment  of  io  Cubic  Meters  (  2700  Gallons)  per  Hour 


Date 

Serial 

Number  of  Experiments 
(9  each  day) 

Number  of  Bacteria  in 

Raw  Water 

Matter  in  Solu- 

Raw  Water  in 

am  Permanga- 

Potassium 

Per  Cent,  of  Reduction 

in  Organic  Matter 

1 

2 

a 

4 

5 

6 

7 

8 

9 

Average 

Organic 

tion  in 

Milligr 

nate  of 

July  7 

4 

10 

7 

5 

19 

7 

8 

9 

9 

2,300 

11. 3 

3° 

i  4 

8 

10 

4 

4 

0 

2 

9 

5 

7 

7 

2,400 

n-3 

26 

4  4 

10 

9 

8 

9 

5 

7 

10 

7 

4 

6 

7 

1 ,960 

1 1.2 

26 

4  4 

1 1 

16 

— 

— 

8 

10 

7 

*5 

12 

23 

13 

1,670 

10.9 

23 

4  < 

15 

6 

10 

4 

5 

— 

8 

4 

6 

6 

4,950 

10.3 

26 

4  4 

16 

7 

8 

10 

5 

8 

6 

3 

5 

10 

7 

95° 

10. 1 

31 

4  4 

17 

9 

7 

10 

1 

■1 

10 

2 

3 

1 1 

6 

920 

9.9 

28 

4  4 

18 

10 

8 

4 

6 

4 

2 

— 

— 

— 

6 

800 

9.8 

23 

4  4 

19 

2 

2 

7 

2 

2 

7 

-» 

a 

3 

880 

9.2 

1 7 

4  4 

21 

0 

1 

1 

6 

0 

1 

— 

— 

— 

1 

55o 

8 

39 

4  4 

25 

M 

16 

9 

6 

1 1 

9 

3 

9  7 

Average 

9 

7 

3,800 

9 

22 

Treatment  of  5  Cubic  Meters  (+1350  Gallons)  per  Hour 


Date 

Serial 

Number  of  Experiments 
(9  each  day) 

a; 

hfi 

r  of  Bacteria  in 
Water 

c  Matter  in  Solu- 
in  Raw  Water  in 
?ram  Permanga- 
of  Potassium 

:nt.  of  Reduction 
ganic  Matter 

1 

2 

3 

4 

5 

6 

7 

8 

9 

A  vera: 

Numbe 

Raw 

'5  <->  3  0 
£ L  0  S  ts 

G 

O 

UC 

U  Z 
<v  •- 
CU 

July  26 

4 

2 

3 

2 

3 

3 

2 

1 

a 

2 

■J 

J 

5,150 

9-5 

40 

“  28 

8 

0 

6 

2 

2 

0 

1 

0 

I 

2 

20,160 

9-5 

36 

“  29 

1 

0 

2 

I 

1 

2 

0 

I 

0 

I 

705 

84 

45 

“  3° 

1 

5 

2 

2 

1 

1 

1 

I 

I 

2 

1,73° 

9.2 

43 

“  31 

1 

2 

0 

I 

1 

0 

1 

1 

0 

I 

1,920 

8.5 

40 

Aug.  1 

1 

1 

O 

2 

1 

1 

0 

4 

I 

1 

1 ,400 

10.5 

32 

“  6 

1 

1 

4 

O 

2 

0 

Average 

1 

2 

IJOO 

10.0 

44 

>4 


The  raw  water  varies  in  number  of  bacteria  from  700  to 
20,000  per  cubic  centimeter.  The  Yecht  is  rather  more  of  a 
ditch  than  a  river.  It  receives  a  great  deal  of  Polder  water 
and  after  heavy  rains  the  number  of  bacteria  is  raised  to 
over  40,000  and  often  to  over  70,000  per  cubic  centimeter, 
while  in  very  dry  weather  the  number  is  reduced  to  under 
700.  The  original  number  of  bacteria  has,  however,  little 
effect  on  the  result  obtained  by  ozonization.  To  complete 
the  table  I  have  added  the  status  of  organic  matter.  When 
instead  of  5  cubic  meters  we  take  15  cubic  meters  we 
obtain  a  less  favorable  bacteriological  result,  as  might  be 
expected.  In  the  meantime  I  became  acquainted  with  what  is 
said  in  a  publication  of  Kaiserliche  Gesnndheitsamt ,  wherein 
Dr.  Ohlmuller  and  Dr.  Prall  furnished  a  report  on  the  “Die 
Behandlung  der  Trinkwassers  mit  Ozon”  (the  treatment  of 
water  with  ozone).  This  publication  was  made  by  authority 
of  the  government,  and  has,  therefore,  the  unquestionable 
stamp  of  reliability  and  impartiality.  In  the  article  referred 
to,  we  find  among  others  the  following  observations : 

[Translated  from  the  German.] 

“It  would  be  an  unjustified  requirement  to  ask  that  a 
water  ozonizing  plant  should  furnish  water  absolutely  free 
from  all  bacteria.  In  no  known  arrangement  of  central  water 
purification  is  this  condition  aimed  at,  nor  is  it  necessary 
considered  from  a  hygienic  point  of  view,  etc.” (See  Arbeiten 
Gesundheitsambt f  Band  8,  p.  159.)  A  reduction  of  bacteria 
to  100  per  cubic  centimeter  is  considered  sufficient.  This 
result  is  readily  obtained  by  ozonization  by  which  the  bac¬ 
teria  (in  Spree  water),  after  the  latter  having  been  rough 
filtered  through  a  Kronke  filter  to  arrest  the  material  in 
suspension,  was  reduced  from  83,700-86,800  to  20-28. 

A  verdict  like  this,  considering  the  origin,  allows  us 
to  confine  ourselves  to  aiming  not  at  complete  sterilization, 
but  at  nearly  complete  sterilization  with  absolute  safety;  but 
the  great  question,  of  course,  is  this:  Those  20  bacteria 


1 5 


which  are  left  over — what  are  they ?  May  they  not  be  the 
most  dangerous  ones  ?  Although  it  was  well  known 
through  experiments  on  a  small  scale  that  pathogenic  bac¬ 
teria  or  disease  germs  offer  feeble  resistance  and  are  easily 
killed,  Drs.  Ohlmuller  and  Prall  experimented  on  a  large 
scale,  viz  :  with  io  cubic  meters  of  water  per  hour  after  infect¬ 
ing  the  water  with  the  bacilli  of  typhus  and  cholera,  viz :  the 
water  contained  +  17,000  cholera  bacilli  per  cubic  centi¬ 
meter,  35,000  typhus  bacilli  and  33,000  coli  bacilli.  Twenty- 
four  tests  were  made  and  in  all  24  sterile  results  were  ob¬ 
tained — not  entirely  satisfied  yet,  they  mixed  infected  water 
with  ordinary  Spree  water  1  to  1.  Before  the  ozonization  the 
total  was  43,800  to  45,107  per  cubic  centimeter,  after  the 
ozonization  5  and  6.  “In  dem  nicht  ozonisirten  wasser 
konnten  die  cholerabachterien  nachgewiesen  werden,  in  dem 
ozonisirten  waren  sie  vernichtet”  (“in  the  water  not  ozonized 
the  cholera  bacteria  could  be  detected ;  in  the  ozonized  water 
they  were  destroyed”).  The  same  tests  were  made  on  a 
larger  scale,  with  the  result  that  ozonization  reduced  the 
number  of  bacteria  from  38,330-16,590  to  8-9,  respectively, 
hence  their  verdict. 

These  investigations  proved  that  the  treatment  of  water 
with  ozone,  as  it  was  done  in  Martinikenfeld,  destroyed  the 
bacteria  of  cholera  and  typhus,  and  it  is  especially  to  be 
observed  that  the  generally  more  resistant  typhus  bacilli, 
despite  the  higher  oxidability  of  the  water,  were  destroyed 
just  as  readily  as  the  less  resisting  cholera  bacilli. 

It  is  generally  known  that  ozone  first  attacks  the  organic 
matter  and  then  the  bacteria,  but  we  succeeded  in  limiting  the 
effect  on  the  organic  matter  and  to  completely  destroy  the 
bacteria.  This  is  shown  in  the  latest  table  of  recent  date,  as 
of  August  it,  where  the  reduction  of  organic  matter  is  in¬ 
considerate,  while  the  bacteriological  result  is  very  good. 


i6 


Treatment  of  io  Cubic  Meters  (-j-  2700  Gallons)  per  Hour 


Date 

Serial 

Number  of  Experiments 
(9  each  day) 

Average 

Number  of  Bacteria  in 

Raw  Water 

Organic  Matter  in  Solu¬ 

tion  in  Raw  Water  in 
Milligram  Permanga¬ 

nate  of  Potassium 

Per  Cent,  of  Reduction 

in  Organic  Matter 

I 

2  3 

4 

5 

6 

7 

8  9 

Aug.  I  I 

3 

3  4 

0 

1 

1 

0 

1  2 

2 

95° 

_  _ 

“  12 

4 

0  4 

0 

1 

0 

1 

2  3 

2 

1,000 

.8  28% 

“  13 

2 

2  2 

4 

2 

0 

1 

6  1  0 

2 

1,030 

8-4  33% 

Average 

2 

We  are  able  to  produce  water  which  is  practically  sterile. 
This  does  not  mean,  however,  that  in  thousands  of  cubic 
meters  per  day  not  a  single  bacteria  will  be  found.  This  is 
practically  impossible.  When,  however,  nine  consecutive 
tests  showed  only  two  bacteria  per  centimeter,  as  the  table 
showed,  we  are  justified  in  calling  this  water  sterile.  We 
are  able  to  leave  it  to  the  choice  of  others  whether  they  desire 
practically  sterile  water  with  only  1  or  2  bacteria  per  cubic 
centimeter  or  a  water  low  of  bacteria  ozonized,  instead  of 
filtered.  The  first,  of  course,  is  the  most  expensive.  Drs. 
Ohlmuller  and  Prall  further  reached  the  following  conclu¬ 
sions  : 

First. — By  the  treatment  of  water  with  ozone  a  remark¬ 
able  destruction  of  bacteria  is  produced,  and  in  this  regard 
ozonization  is  in  general  superior  to  separation  of  bacteria  by 
sand  filtration. 

Second. — The  cholera  and  typhus  bacilli  are  destroyed. 

Third. — Viewed  from  a  chemical  point  of  view  the 
water  is  affected  only  insofar  that  the  oxidability  is  reduced 
and  free  oxygen  increased,  both  of  which  mean  an  improve¬ 
ment  of  the  water. 


>7 


Fourth. — The  ozone  which  is  introduced  in  the  water 
is  of  no  importance  from  a  technical  or  health  affecting  con¬ 
sideration,  as  it  readily  changes  into  oxygen. 

Fifth. — The  treatment  of  it  improves  the  water  by  mak¬ 
ing  it  colorless. 

Sixth. — The  taste  is  not  affected,  etc. 

Primary  advantages  are : 

First. — That  it  is  a  clean  mechanical  arrangement  se¬ 
curing*  a  perfect  regularity  in  operation  without  interruption 
from  ice,  conditions  of  weather,  etc. 

Second. — That  in  times  of  threatening  danger  by  epi¬ 
demics  the  quantity  of  ozone  can  be  increased  or  the  amount 
of  water  handled  decreased. 

Third. — The  capacity  of  the  plant  can  be  readily  in¬ 
creased  as  it  simply  involves  a  question  of  multiplying  the 
units  of  apparatus. 

Fourth. — It  allows  greater  freedom  in  the  choice  of 
sources  of  supply,  and,  therefore,  enters  into  the  question  of 
cost  of  transportation.  These  questions  can,  of  course,  not 
be  exemplified  in  figures.  The  transportation  of  a  water 
supply  from  long  distances  may  involve  millions.  Again  the 
cost  of  the  installation  depends  on  the  quality  of  the  water 
and  size  of  the  installation. 

Mr.  Vosmaer  claimed  the  plant  required  a  minimum 
of  attendance  and  that  it  is  practically  self-operative. 
During  the  entire  tests  the  only  attention  required  was 
the  keeping  up  of  steam  to  workable  pressure,  and  exam¬ 
ining  once  a  day  the  oil  cups  on  the  movable  parts  of  the 
pumps,  etc.  In  other  words,  the  plant  practically  ran 
itself  and  the  result  obtained  (see  table)  unquestionably 
sustained  all  that  has  been  claimed  for  the  Vosmaer 
system. 


i  8 


Remarks  by  Dr.  van ’t  Hoff,  bacteriologist  for  the  De¬ 
partment  of  Water  Supply  of  the  City  of  Rotterdam,  at 
meeting  referred  to  : 

I  believe  that  the  absence  of  complete  sterilization  in 
ozonized  water,  as  discussed  by  Mr.  Vosmaer,  is  attribu¬ 
table  only  to  the  presence  of  spore  bacteria  which  are 
more  resistant  than  the  pathogenic.  That  being  the  case 
it  is  justifiable  to  say  of  this  water  that  it  is  so  barren 
of  bacteria  that  it  borders  on  sterility. 

OZONIZATION  OF  DRINKING  WATER: 

What  ozone  is,  and  why  it  is  claimed  to  be  efficient  and 
reliable  as  a  positive  remedy  against  the  introduction  and 
spread  of  pathogenic  germs,  such  as  typhoid  fever,  cholera, 
etc.,  through  drinking  water,  will  be  better  understood  by 
reference  to  what  has  been  said  on  the  subject  by  well  known 
scientists. 

M.  M.  Pattison  Muir,  M.  A.,  Fellow  and  Professor  in 
Chemistry  of  Gonville  and  Cains  College,  Cambridge,  Eng¬ 
land,  in  “The  Story  of  the  Wanderings  of  Atoms,"  says: 
“When  oxygen  is  submitted  to  the  action  of  the  silent  electric 
discharge  a  portion  of  the  ozygen  is  changed  into  a  sub¬ 
stance  which  is  a  more  energetic  oxidizer  than  ozygen.  This 
substance  converts  mercury,  at  the  ordinary  temperature, 
into  black  oxide  of  mercury,  a  reaction  which  is  not  accom¬ 
plished  by  oxygen ;  when  brought  into  contact  with  a  solu¬ 
tion  of  iodide  of  potassium  it  produces  oxide  of  potassium, 
iodine,  and  oxygen,  this  also  being  a  reaction  which  oxygen 
does  not  effect.  When  oxygen  which  has  been  submitted  to 
the  action  of  the  silent  electric  discharge  is  cooled  to  about 
— i8o°  C.  ( — 2920  F.)  a  blue  liquid  is  formed;  if  this  is 
allowed  to  evaporate  oxygen  passes  off  as  a  gas,  and  the 
modification  of  oxygen  called  ozone  remains,  presenting  the 
appearance  of  a  very  dark  blue  liquid,  and  boiling  at — 1060 
C.  ( — 2 1 40  F. ).  Liquid  oxygen  boils  at  about  —  1810  C. 


l9 


( — -2 940  F.).  Ozone  is  completely  changed  into  oxygen  by 
heating  to  low  redness;  the  weight  of  the  oxygen  obtained 
is  equal  to  the  weight  of  the  ozone  used;  the  volume  of  the 
oxygen,  however,  is  one  and  one-half  times  as  great  as  the 
volume  of  the  ozone.  Ozone  is  one  and  one-half  times 
heavier  than  oxygen,  bulk  for  bulk;  and,  as  a  contraction  of 
volume  attends  the  formation  of  ozone  from  oxygen,  ozone 
may  be  called  condensed  oxygen. 


WHAT  OZONE  DOES: 

It  purifies  air  and  when  introduced  into  smoky  rooms 
all  smell  disappears.  It  can  he  used  with  advantage  for  the 
purpose  of  purifying  air  in  public  buildings,  theatres,  club 
rooms,  and  in  fact  wherever  crowds  congregate.  It  may 
also  enter  into  therapeutic  use  for  curing  first  stages  of  con¬ 
sumption,  and  in  many  ways  in  manufacturing  industries, 
for  instance :  the  treatment  of  linum  usitatissimum  before  it 
can  be  combed  into  flax  can  be  greatly  simplified  and  cheap¬ 
ened  and  the  quality  of  the  flax  improved  by  the  use  of 
ozone,  since  it  takes  the  glue  from  the  raw  flax  and  at  the 
same  time  imparts  an  improved  color  to  it;  but  its  great  field 
lies  in  the  direction  of  purifying  drinking  water. 

The  following  is  a  translation  of  the  article  by  Drs. 
Ohlmuller  and  Prall,  referred  to  by  Mr.  Vosmaer  in  his 
address  before  the  Society  of  Hydraulic  Engineers  of  Hol¬ 
land,  convened  at  ’s-Gravenhage  on  September  12  and  13, 
1902 : 

The  Treatment  of  Drinking  Water  with  Ozone 
By  Dr.  Ohlmuller  and  Dr.  Fr.  Prall 

When  in  the  year  1891  Froehlich  and  his  cooperators 
had  shown  the  way  of  obtaining  ozone  in  any  quantity  and 
degree  of  concentration  desired  from  the  oxygen  of  the 


20 


atmospheric  air,  the  Imperial  Board  of  Health  determined 
to  demonstrate  the  action  of  this  substance  upon  bacteria. 
These  inquiries  have  confirmed  previous  observations  bearing 
on  this  question,  and  have  proved  especially,  “that  ozone  has 
a  most  powerful  destructive  influence  on  bacteria  present  in 
water ,  if  the  zmter  is  not  too  strongly  contaminated  with  dead 
organic  substances ;  the  result  is  the  same  when  the  quantity 
of  lifeless  organic  substance  is  oxidized  to  a  certain  degree." 
On  the  strength  of  this  result  it  was  not  too  bold  to  hope  that 
after  the  production  and  application  had  been  further  de¬ 
veloped  it  would  be  possible  to  make  the  application  of  ozone 
practically  useful,  especially  with  a  view  to  the  destruction  of 
bacteria  in  drinking  water. 

The  first  attempts  in  this  direction  were  made  by  Tyn¬ 
dall  and  his  collaborator  Schneller.  These  attempts  induced 
Tyndall  to  build  a  large  experimental  station  at  Ouds- 
hoorn  near  Leyden.  There  water  taken  from  the  Old 
Rhine  was  treated  with  ozone.  V an  Ermengem  tested  the 
experiments  and  stated  a  satisfactory  purification  of  the 
water.  Tyndall  then  exhibited  at  the  Paris  hygiene  exhibi¬ 
tion  in  1895  an  apparatus  with  a  purifying  capacity  of  2  cubic 
meters  per  hour.  Since  1895  Abraham  and  Marmier  have 
occupied  themselves  with  the  process,  particularly  with  a 
view  to  the  practical  application  of  ozone.  Otto  and  Gosselin 
and  also  Vosmaer  have  done  good  work  in  the  perfection  of 
the  apparatus.  Otto’s  apparatus  acts  well,  as  was  shown 
by  the  tests  applied  by  Loir  and  Fernbach. 

In  1897  the  process  was  exhibited  at  the  Brussels  Ex¬ 
position  and  this  led  to  the  construction  of  an  installation  at 
Blankenberghe  near  Ostend,  with  a  capacity  of  2000  cubic 
meters  per  day;  soon  after,  however,  it  was  given  up  again, 
as  it  did  not  answer  the  expectations. 

Another  installation  was  built  in  1898  by  Abraham  and 
Marmier,  by  order  of  tbe  municipal  corporation  of  Lille;  its 
capacity  was  35  cubic  meters  per  hour;  the  water  was  ob- 


21 


tainecl  from  wells  in  Emmerin.  A  scientific  committee 
appointed  by  the  corporation  submitted  the  installation  to  a 
thorough  bacteriological  and  chemical  test  and  found  it  to 
answer  every  requirement. 

In  1900  the  process,  according  to  the  Abraham-Marmier 
system,  was  on  view  at  the  Paris  exhibition ;  the  installation 
was  described  by  Krull. 

There  is  also  an  installation  at  Schiedam  near  Rotter¬ 
dam;  it  has  been  built  on  Vosmaer’s  system  and  has  a 
capacity  of  20  cubic  meters  per  hour. 

Messrs.  Siemens  &  Halske  in  Berlin,  who,  as  has  been 
stated,  first  made  ozone  practically  applicable,  have  exerted 
themselves,  since  the  possibility  of  purifying  drinking  water 
by  ozone  was  pointed  out,  to  perfect  the  process  by  the  con¬ 
struction  of  apparatus  both  for  the  production  and  the  appli¬ 
cation  of  ozone.  Weyl  had  an  opportunity  of  testing  the 
apparatus  while  still  in  construction. 

Guided  by  the  various  results  obtained  they  constructed 
a  fairly  large  experimental  station  with  a  capacity  of  10 
cubic  meters  per  hour,  at  Martinikenfeld,  on  the  northeastern 
boundary  of  Berlin. 

The  object  of  this  station  was  not  only  to  give  those  in¬ 
terested  in  the  process  an  opportunity  to  get  acquainted  with 
it,  but  also  to  demonstrate  its  practicability.  The  installa¬ 
tion  has  been  improved  in  various  ways  by  hygienic  and 
technical  specialists  and  by  members  of  scientific  societies. 
The  experiments  made  by  the  firm  itself  at  the  station,  from 
a  technical  point  of  view  as  well  as  with  regard  to  the  condi¬ 
tion  of  the  water  treated  with  ozone,  have  been  dealt  with  by 
Erlwein  in  his  treatise,  “Trinkwasserreinigung  durch  Ozon 
nach  dem  System  von  Siemens  &  Halske  (A.-G. )  Berlin." 

Owing  to  the  great  interest  that  had  been  taken  in  the 
subject  of  purification  of  drinking  water  by  ozone,  the  Im¬ 
perial  Board  of  Health  decided  to  make  a  series  of  experi¬ 
ments  at  the  above  station. 


22 


The  arrangement  of  the  Martinikenfeld  station  is  clearly 
shown  by  the  drawing  below. 


Ozone  is  prepared  by  pressing  air  by  means  of  an 
air  pump  into  the  drying  apparatus.  It  consists  of  a 


23 


refrigerator,  the  hose  of  which  cools  down  the  air  and 
consequently  reduces  its  moisture.  The  air  dried  in  this 
way  passes  into  the  ozonizer,  a  box  in  which  four  pairs  of 
plates  made  of  glass  and  metal  alternately  have  been  ar¬ 
ranged.  Between  these  “blue  glow  discharges”  takes  place, 
produced  by  an  alternating  current  of  10,000  to  15,000  volts 
tension.  When  the  air  passes  through  the  spaces  between 
the  plates  in  which  the  discharges  take  place,  its  oxygen  is 
partly  transformed  into  ozone.  The  ozonized  air  then  passes 
upward  through  the  sterilizing  tower. 

In  order  to  bring  about  the  action  of  the  ozonized  air 
upon  the  water  to  be  treated  the  following  arrangement  has 
been  made : 

By  means  of  a  pump  the  water  (taken  from  the  Spree) 
is  raised  to  a  basin  for  raw  water ;  from  here  it  runs 
by  gravity  through  a  Kronke  filter  (of  which  there  are  two), 
where  the  visible  suspended  matter  is  separated,  and  col¬ 
lects  in  a  second  basin.  This  filtered  water  is  led  from 
there  to  the  sterilizing  tower.  The  tower  is  built  of  brick, 
5  meters  high  and  one  meter  in  diameter ;  the  inside  is 
cemented  ;  it  is  closed  all  around  with  the  exception  of  the 
inlets  and  outlets  for  ozonized  air  and  water ;  the  top  is 
walled  up;  the  bottom,  which  is  provided  on  one  side  with  a 
discharge  pipe  for  the  water,  is  placed  in  a  water  basin.  This 
arrangement  makes  it  impossible  for  the  air  entering  at  the 
bottom  to  escape ;  it  is  forced  to  go  upwards  through  the 
tower  and  then,  as  far  as  it  has  not  been  used  up,  to  escape  at 
the  top  through  a  discharge  pipe  and  to  return  to  the  ozoniz¬ 
ing*  apparatus.  The  water,  however,  runs  in  the  opposite 
direction ;  it  enters  at  the  top  and  runs  out  at  the  bottom. 
Consequently  a  countercurrent  system  is  applied.  In  order 
to  make  the  ozone  act  upon  the  water  under  the  most  favor¬ 
able  circumstances,  the  water  is  spread  over  the  greatest 
surface  possible.  The  ozonizing  space  proper  is  therefore 
filled  with  pebbles  as  big  as  eggs,  which  are  arranged  upon  a 
frame.  By  means  of  a  douche  and  a  sieve  the  water  is 


24 


divided  into  numerous  jets,  falls  on  the  pebbles  and  drips 
down  again,  while  all  the  time  it  is  exposed  to  the  action  of 
ozone;  after  this  it  runs  into  the  basin  in  which  the  tower 
stands,  and  on  this  basin  running  over,  it  is  collected  in  a 
reservoir. 

In  order  to  test  the  efficiency  of  the  installation  a  num¬ 
ber  of  experiments  were  made.  They  were  executed  on  the 
following  plan:  First  the  refrigerator  was  worked  for  one 
hour,  so  as  to  make  it  reach  its  maximum  capacity  for  drying- 
air;  then  the  production  of  ozone  began.  In  order  that  the 
sterilizing-  tower  might  always  be  in  the  same  condition  at 
the  beginning  of  the  experiment  ozonized  air  and  water  from 
the  Charlottenburg  waterworks  were  made  to  run  in  counter- 
currents  through  the  tower  for  half  an  hour  or  an  hour. 
Then  the  real  test  began ;  the  water  to  be  treated  was  con¬ 
ducted  through  the  tower;  after  half  an  hour  samples  of 
water  were  taken  at  regular  intervals  from  the  raw  water 
basin,  from  the  basin  for  filtered  water  and  from  the  sterili¬ 
zation  tower  before  the  water  had  reached  the  ‘‘overrunning” 
basin ;  for  this  purpose  a  metal  tube  bad  been  put  in  the  wall 
of  the  tower,  the  mouth  of  which  tube  was  sterilized  before 
the  beginning  of  the  test  by  means  of  a  flame.  The  samples 
for  the  bacteriological  tests  were  taken  with  the  usual  pre¬ 
cautions  and  then  dealt  with  at  once  with  a  view  to  the 
determination  of  the  number  of  bacteria.  Of  the  raw  and  the 
filtered  water  0.2  cubic  centimeter  or  corresponding  dilu¬ 
tions  with  sterile  water,  of  the  ozonized  water  o.  1  cubic 
centimeter  was  used  for  the  culture.  Plates  with  ordinary 
gelatine  were  prepared,  in  order  to  obtain  results  that  could 
lie  compared  with  those  arrived  at  elsewhere,  and  also  plates 
with  a  culture  substance  consisting  of  gelatine,  Agar  & 
Heyden’s  culture  substance,  as  it  had  been  proved  that  in  the 
latter  the  bacteria  occurring  in  water  developed  in  greater 
numbers.  These  numbers  are  therefore  nearer  to  the  truth. 
The  plates  obtained  from  non-ozonized  water  were,  in  accord¬ 
ance  with  Neisser's  method,  “counted”  after  two  days;  those 


25 


prepared  with  ozonized  water  after  five  days.  All  the  plates 
were  kept  in  a  culture  case  at  22  °.  Moreover  the  raw,  the 
filtered  and  the  ozonized  samples  were  submitted  to  a  chemi¬ 
cal  examination;  its  oxidability,  the  quantity  of  ammonia, 
nitrous  and  nitric  acids  were  determined,  and  in  the  middle  of 
each  test  the  quantity  of  residue  at  1160  was  fixed.  Finally 
the  appearance  of  the  water  as  to  color  and  clearness  and  its 
taste  were  noted. 

The  production  of  ozone  during  these  experiments  was 
managed  in  such  a  way  that  a  concentration  of  about  3  to  5 
grams  per  cubic  meter  of  air  was  obtained ;  during  each 
experiment  the  quantity  of  ozone  produced  was  only  subject 
to  insignificant,  inevitable  fluctuations.  The  percentage  of 
ozone  was  during  the  experiment  determined  every  half  hour 
before  and  behind  the  sterilizing  tower.  As  a  rule  30  cubic 
meters  of  air  went  through  the  testing  apparatus;  in  two 
tests  40  centimeters  were  employed  with  the  same  ozone  con¬ 
centration,  in  order  to  determine  the  result  of  this  increase. 

The  quantity  of  water  treated  with  ozone  varied  from 
5  to  10  cubic  meters  per  hour.  Spree  water  and  a  mix¬ 
ture  of  such  water  and  water  from  the  Charlottenburg  water- 
works  in  various  proportions  were  employed  to  vary  the 
oxidability  and  the  number  of  bacteria  within  certain  limits, 
as  former  experiments  had  shown  that  just  these  properties 
of  the  water  are  decisive  for  the  action  of  ozone.  A  glance 
at  the  condition  of  Spree  and  of  mixed  water  shows  the  mini¬ 
mum  and  the  maximum  values  determined  by  the  examina¬ 
tion  of  these  two : 


Oxidability  in 
Milligram  of 
Oxygen 

N  itrous 
Acid 

Nitric 

Acid 

Number  of  Bacteria 

Source  of  Water 

Left  after 
Evaporation 

Ammonia 

Ordinary  Gelatine 

Gelatine,  Agar  and 
Heyden  Food 

I.  Spree  Water 

172.4—233.6 

7.52 — 10  88 

O 

M 

1 

1 

c 

O 

o-Spur 

35,700—185,800 

48,000 — 41  2,400 

II.  Spree  Water 
after  Filtrat’n 

I  <S  1 . 4 — 204  2 

6.l6 —  7-12 

0.0 — 0  24 

O 

o-Spur 

5,700—  26,950 

8,900 —  60,300 

11 1.  Mixed  Water 

232.8— 33O.O 

4.24 —  6.l6 

G.O - O.24 

O 

0 

35,700—  48,000 

70,400  --  86,8oo 

26 


W  ater  from  the  Charlottenburg  waterworks — being 
subterraneous  water — is  richer  in  dissolved  substances  and 
power  in  organic  matter  than  Spree  water ;  consequently  a 
greater  proportion  of  the  same  in  a  mixture  causes  an 
increase  of  residue  and  a  decrease  of  oxidability.  By  filtra¬ 
tion  through  the  Kronke  filter  the  number  of  bacteria 
decreased.  The  water  indicated  Sub.  II  and  III  passed 
through  the  sterilizing  tower ;  consequently  ozone  acted 
on  water  of  such  a  nature  that  per  cubic  centimeter  5700- 
48,000  bacteria  developed  in  ordinary  gelatine,  and  8900- 
86,800  in  other  culture  substances.  The  latter  numbers 
must  be  looked  upon  as  the  correct  ones,  the  former  having 
been  adduced  only  to  render  comparison  with  other  results 
possible. 

For  the  sake  of  comparison  with  the  above  two  kinds  of 
water  the  composition  of  water  from  the  old  Rhine  near  Oud- 
shoorn  and  that  of  the  well  water  at  Emmerin,  both  of  which 
were  also  submitted  to  the  ozone  treatment,  may  be  stated 
here : 


Source  of  Water 

f1 

Left  After  Evap¬ 
oration 

Oxidability  in 
Milligram  of 
Oxygen 

Ammonia 

Nitrous  Acid 

Nitric  Acid 

Number  of  Bac¬ 
teria 

Old  Rhine,  Unfiltered  .  . 

222 

6.0 

0.1 

O 

0.6 

10,802 

“  “  Filtered  .  .  . 

284 

2-5 

0  3 

O 

1-4 

385 

Spring  Water . 

— 

0.8 

00 

0-5 

20.0 

988 — 2,200 

The  water  from  the  old  Rhine,  as  subjected  to  the  ozone 
process  (filtered)  possessed  a  lower  oxidability  and  a  smaller 
number  of  bacteria  than  Spree  or  mixed  water ;  the  oxida¬ 
bility  of  Emmerin  well  water  was  still  less,  while  the  number 
of  bacteria  was  greater,  though  it  did  not  come  up  to  the 
number  found  in  the  two  kinds  of  water  treated  here. 


27 


In  the  Martinikenfeld  experimenting  station  water  of  a 
more  unfavorable  condition  was  purposely  subjected  to  the 

ozone  treatment,  in  order  to  determine  the  efficacy  of  the 
system. 

J 

Results  of  the  Bacteriological  Examination 

In  order  to  render  it  possible  to  state  to  what  extent 
water  bacteria  are  killed  by  ozone,  the  capacity  of  the  ozone 
apparatus  and  the  quantity  of  water  treated  must  be  known. 
Besides  the  number  of  bacteria  in  the  filtered  water  passed 
through  the  apparatus,  its  oxidation  coefficient  before  and 
after  the  treatment  are  also  important.  The  results  in  this 
respect  are  stated  in  the  table  below ;  each  number  of  bacteria 
is  the  average  found  in  two  plates. 

Generally  speaking  the  bacteria-destroying  power  of 
ozone  was  very  considerable;  in  the  case  of  bacteria  culti¬ 
vated  in  gelatine  out  of  5700  to  48,000  only  1  to  28  remained 
alive ;  in  the  case  of  those  cultivated  in  other  substances  out 
of  8900  to  86,800  only  1  to  32.  If  the  causes  of  less  effica¬ 
cious  action  are  to  be  ascertained,  they  are,  as  was  to  be 
expected,  to  be  found  in  the  inferior  condition  of  the  water 
employed.  In  the  case  of  unmixed  (filtered)  Spree  water 
(experiments  1  and  2)  the  number  of  surviving  bacteria 
was  greater  than  in  the  case  of  mixed  water.  The  quantity 
of  water  treated  proved  to  be  immaterial  in  this  respect ; 
the  results  were  equally  favorable  whether  5,  7.5  or  10 
cubic  meters  were  used.  Experiment  8  forms  an  exception ; 
this  will  be  referred  to  later  on. 

On  the  other  hand,  the  conclusion  suggests  itself  that 
the  final  result  is  determined  by  the  quantity  of  ozone  acting 
upon  1  liter  of  water  and  the  amount  of  oxidizable  sub¬ 
stances  (especially  of  dead  organic  matter  and  the  number 
of  bacteria).  In  experiment  3,  24.0-26.3  milligrams  of 
ozone  were  employed;  the  oxidability  was  comparatively 
high, — 5.84-6.16  out  of  the  14,300-17,400  bacteria  8-12  sur¬ 
vived.  On  the  other  hand,  in  the  case  of  experiment  10  only 
12.1-13.5  milligrams  of  ozone  (about  half  the  quantity) 


N  umber  of  Test 


23 


1 


2 


n 

O 


4 


5 


G 


8 


9 


10 


11 


12 


13 


Day  of  Test 

1 

1 

Hour  of  Test  Taken 

Kind  of  Water 

1 

Milligram  of  Water 

Milligram  of  Air 

Milligram 
of  Ozone 
per  Liter 
of  Air 

M  illigram 
of  Ozone 
per  Liter 
of  Water 

Milligram 
of  Oxygen 

Reduction  in  Organic  Matter 

Bacteria  per  Cubic  Centi¬ 
meter 

Ordinary 

Gelatine 

Gelatine 
Agar  and 
Heyden 

D 

u 

O 

u_ 

D 

PQ 

U 

D 

< 

■a 

- 

73, 

p, 

< 

O, 

£ 

D 

C/3 

£ 

g! 

o 

Ul  N 

D 

M  § 

N 

O 

G 

.2 

D  G 

N 

<1 

N 

O 

c 

o 

D  'Z 
^  G 

D  £ 

ca  5 

N 

O 

.2 
v  ci 

N 

O 

G 

«.2 

J- 

o  g 

C-  N 

D 

22  G 
w  O 

N 

O 

G 

O 

D  G 
<£.2 

<  G 

^  o 

N 

o 

|  27.  III. 

11 

1 

3 

U 

D  (D 

D  -»_> 
u  d 

5,100 

5,010 

4,980 

30.100 

31.100 
31,000 

2.91 

3.49 

3.72 

2.24 

3.07 

3.04 

17.2 
21.5 

23.2 

3  55 
3.63 
3.66 

7.12 

6.16 

6.40 

4  56 
4.64 
4.96 

2.56 

1.52 

1.44 

43,900 
48  000 
40,800 

22 

24 

28 

85.700 

83.700 
86,800 

20 

24 

28 

30.  III. 

11 

1 

o 

O 

iD  d 

D  ^ 

Jr  G 

7,560 

7,200 

7,500 

30,300 

31,000 

29.600 

4.13 

4.42 

4.41 

3.09 

3.43 

3.37 

16.5 
19  0 

17.5 

3.80 

3.86 

3.84 

6  96 

7  04 
7.04 

5.44 

5.44 

5.44 

1.52 

1.60 

1.60 

36,700 

36.700 

35.700 

27 

26 

26 

70,400 

83.700 

84.700 

23 

25 

22 

2  IV. 

11 

l 

3 

D  r*  U 

D  D 

p.|  5 

<N  r-T 

5,100 

5,160 

5,000 

30,000 

30,100 

30,700 

4.44 

4  50 
3.91 

3.79 

3.84 

3.30 

26.1 

26.3 

24.0 

3.16 

3.20 

3.14 

5.84 

6.00 

6.16 

4.16 

4.40 

4.56 

1.68 

1.60 

1.60 

16.300 

14.300 
17,400 

8 

8 

12 

33,200 

34.700 

35.700 

5 

10 

11 

10.  IV. 

1130 

1 

3 

D  }_, 

D  .G  D 

r— '  TT 

4,740 

4,860 

5,020 

30,100 

30,100 

30,100 

4.07 

3  80 
3.85 

3.60 

3.29 

3.32 

25.8 

23.5 

23.0 

2.30 

2.55 

2.63 

4.72 

4.48 

4.64 

3.76 

3.76 

3.84 

0.96 

0.72 

0.80 

6,200 

5,700 

6,800 

5 

5 

4 

15,500 

14,900 

14,700 

3 

2 

7 

15.  IV. 

1 

3 

5 

O  £-  U 

o  .2  o 
rt  *z 

c/; «  $ 

i-l  O! 

5,300 

5,220 

5,490 

30,700 

31.100 

30.100 

3.48 

3.50 

3.66 

2.82 

2.88 

3.02 

20.2 

20.9 

20.0 

3.30 

3.20 

2.99 

5.20 

5  04 
4-96 

4.24 

4.24 

4  00 

0.96 

0.80 

0.96 

8.700 

6,900 

5,800 

13,500 

9.900 

8.900 

3 

3 

1 

18.  IV. 

11 

1 

3 

<U  C  !- 
0.-0 

5,280 

5,100 

5,160 

31,100 

30,900 

31,100 

3  72 
3.84 
3.89 

3.05 

3.19 

3.23 

21.9 

23.3 

23.4 

3.43 

3.39 

3.42 

4.96 

4.96 

4.88 

4.16 

4.00 

4.00 

0.80 

0.96 

0.88 

15,300 

15,400 

12,900 

4 

3 

6 

34,200 

29,300 

28,400 

3 

2 

3 

22.  IV. 

H30 

1 

O 

o  J.  u 

o ._  o 
c3  ■“ 
O.—  ctf 

C/J^> 

5,100 

5,100 

5,100 

30,100 

30,800 

30,700 

3.13 

3.24 

3.42 

2.42 

2.60 

2.77 

18.5 
196 

20.6 

3.75 

3.42 

3.43 

4.88 

5.04 

5.20 

4.00 

4.24 

4.32 

0.88 

0.80 

0.88 

6.550 

6,950 

6,750 

o 

i 

13,050 

14,500 

19,350 

o 

O 

1 

5 

25.  IV. 

1130 

1 

3 

D  £  Jx 

D  •-  D 
*-•  G 

G 

7,480 

7,260 

7,440 

30.100 

80.100 
30,000 

3  20 
3.12 
3.23 

2.50 

2.32 

2.37 

12.6 

12.9 

13.0 

2.53 

8.03 

3.16 

5.36 

5.68 

5.68 

4.56 

4.96 

4.96 

0.80 

0.72 

0.72 

22,250 

26,150 

25,000 

13 

zer 

flossen 

64,700 

69,300 

63,900 

16 

32 

14 

6.  V. 

11 

1 

3 

o  C  >-> 
o  .0  o 
ci  *2 
O.—  ctf 

C/2-^> 

r-H 

7,560 

7,320 

7,340 

41,100 

40,900 

40,500 

4  66 
3.71 
3.38 

4.02 

3.08 

2.78 

25.3 

20.7 

18.6 

2.95 

3.09 

2.93 

4.24 

4.24 

4.24 

3.44 

3.44 

3.52 

0.80 

0.80 

0.72 

7,550 

7,950 

7,950 

2 

3 

2 

18,350 

19,800 

19,000 

1 

2 

1 

9.  V. 

12 

yso 

3 

V  C  *H 

D  .G  D 
*-•  rt  *-» 
Qh«t-H  G 

C/.  ^  > 

7,500 

7.560 

7,440 

31.100 

30,000 

30.100 

3.17 

3.04 

3.35 

2.41 

2.27 

2.56 

13.1 

12.1 

13.5 

2.87 

3  79 

2.88 

4  32 
4.32 
4.40 

3.52 

3.52 

3.60 

0.80 

0.80 

0.80 

16.950 
17,700 

26.950 

3 

3 

5 

32,350 

35,000 

62,900 

3 

3 

6 

15.  V. 

11 

1 

3 

D  £  *-• 

D  .G  D 

J;  rt 

U 

r- 1  TJ<  ^ 

7,200 

7,200 

7,320 

30.700 

30.700 
31,100 

3.50 

3  71 
3.78 

2.77 

2.94 

3.08 

14.9 

15.8 

16.1 

2.78 

2.92 

2.98 

4.40 

4.48 

4.48 

3.52 

3.60 

3.68 

0.88 

0.88 

0.80 

6,750 

9,000 

10,000 

5 

2 

2 

16,650 

19,700 

21,550 

11 

5 

2 

24.  VI 

11 

12 

1 

D  r-  J_, 

D  .23  d 

I-l  cj 

Cu-2  G 

r— i  r-^ 

10,200 

9,800 

10,100 

40,800 

40,000 

40,000 

5.45 

5.18 

4.66 

4.25 

4.01 

3.41 

21.8 

21.1 

18.5 

4.43 

4.28 

4  61 

5.76 

5.76 

5.76 

4.80 

4.80 

4.80 

0.96 

0.96 

0.96 

16  850 
17,350 
19,400 

!) 

3 

7 

32,150 

50,000 

42,350 

*) 

7 

11 

27.  VI. 

11 

12 

1 

D  C  , 

D  •—  ^ 
u  (4  V 

r— (  r-l  ^ 

9.800 

10,400 

10,200 

30,ii00 

30.000 

31,000 

5.90 

5.57 

5.57 

4.37 

3.98 

4.03 

18.1 

16.1 

16.9 

4.23 

4.20 

4.28 

6.08 

6.00 

6.00 

4.88 

4.88 

4.88 

1.20 

1.12 

1.12 

10,000 

10.200 

8,900 

6 

7 

6 

22,250 

25,300 

27.550 

9 

9 

11 

f 


o 


n 


29 


was  used;  the  oxidability,  however,  was  lower,  4.32-4.40 
and  consequently  in  spite  of  the  greater  number  of  bacteria 
(16,950-26,950)  only  3-5  survived.  That  in  the  case  of 
experiment  3  so  much  ozone  was  used  up  by  the  dead 
organic  matter,  is  proved  by  the  difference  between  the  oxi¬ 
dation  coefficients  before  and  after  the  ozone  treatment;  in 
this  case  it  amounted  to  from  1.60  to  1.68,  in  experiment  10, 
on  the  other  hand,  only  0.80  milligrams. 

The  unfavorable  result  of  experiment  8  is  to  be  ac¬ 
counted  for  in  the  same  way;  here  high  oxidability  (5.36- 
5.68  milligrams)  and  a  great  number  of  bacteria  (22,250- 
26,150)  coincided  with  the  small  quantity  of  ozone  em¬ 
ployed  (12.6-13.0  milligrams). 

That  the  result  depends  to  a  greater  extent  upon  a  low 
oxidation  coefficient  of  the  water  than  upon  a  great  number 
of  bacteria,  was  shown  by  previous  experiments ;  when  the 
oxidability  was  greater,  the  destruction  of  the  bacteria  be¬ 
came  more  difficult;  in  distilled  water  it  took  place  very 
quickly.  With  these  new  experiments,  too,  the  oxidation 
coefficient  played,  generally  speaking,  the  same  part.  Still  it 
must  cause  some  surprise,  that  in  some  cases  in  which  both 
the  oxidability  and  the  number  of  bacteria  were  low,  the 
result  did  not  answer  the  expectations.  So,  for  instance,  in 
the  first  samples  of  water  in  experiments  4  and  11,  showing 
a  consumption  of  oxygen  of  4.72  respectively  4.40  milli¬ 
grams,  5  bacteria  survived  each  time  out  of  6200,  respec¬ 
tively  6750.  This  number  seems  too  high  as  contrasted 
with  the  result  of  experiments  6  and  11,  when  with  an 
oxidability  of  4.96  milligrams  15,300  bacteria  were  all 
destroyed  with  the  exception  of  four.  The  quantity  of 
ozone  employed  does  not  sufficiently  account  for  this  result. 


To  1  I. iter 
of  Air, 

Milligram  of 
Ozone 

To  1  T  iter  of 
Water, 
Milligram  of 
Ozone 

Of  this  Used 
Up  Milligram 

Experiment  4 . .  . 

4.07 

25.8 

2.30 

“  n . 

3-5° 

T4-9 

2.78 

“  6 . 

3-72 

21.9 

3-43 

30 


From  this  it  appears  probable  that  these  results  are  to 
be  ascribed  to  the  presence  of  bacteria  of  greater  resistance. 
The  question  arises  if  these  cannot  be  destroyed  by  increasing 
the  concentration  of  the  ozone.  This  is  not  the  case ;  the 
above  table  concerning  these  three  experiments  shows  that 
the  consumption  is  not  proportionate  to  the  concentration ; 
when  the  latter  was  highest  (experiment  4)  the  consumption 
was  smallest.  The  condition  of  the  water,  especially  its  oxi¬ 
dation  coefficient  and  the  number  of  bacteria  and  the  kinds 
of  these,  is  decisive  for  the  result.  A  concentration  of 
about  3.0-5. 5  grams  ozone  in  1  cubic  meter  of  air,  as  applied 
in  these  experiments,  is  sufficient.  Still  though  in  the  case 
of  the  experiments  in  the  Lille  installation  concentrations  of 
5. 8-9.5  grams  were  applied,  some  germs  of  bacillus  subtilis 
survived.  Abraham  does  not  think  it  advisable  to  go  below 
a  concentration  of  4-5  grams. 

When  the  bacteriological  results  of  these  experiments 
are  compared  with  those  obtained  at  Lille  and  Oudshoorn, 
the  Martinikenfeld  experimenting  station  has  shown  a  satis¬ 
factory  capacity.  That  in  the  former  fewer  or  no  bacteria 
survived,  is  to  be  ascribed  to  the  condition  of  the  water  with 
which  the  experiments  were  made  there.  In  Oudshoorn  the 
filtered  water  from  the  Old  Rhine  contained  385  bacteria, 
the  oxygen  consumption  being  2.5  milligrams;  the  well 
water  of  Emmerin  near  Lille  contained  988-2200  bacteria ; 
the  oxidability  being  as  low  as  0.8  milligrams.  In  the  water 
used  for  the  inquiries  here  the  number  of  bacteria  varied 
between  5700  and  48,000,  the  oxidability  being  from  4.24  to 
7.12  milligrams.  In  Oudshoorn  perfect  sterility  was  obtained, 
in  Lille  specimens  of  bacillus  subtilis  occasionally  escaped;  in 
these  experiments  1  to  28  bacteria  survived  (on  gelatine 
plates).  In  spite  of  the  water  being  of  inferior  condition,  it 
has  often  been  observed  that  one  of  the  two  plates  that  sup¬ 
plied  the  above  averages  was  sterile  ;  this  was  the  case  with 
experiments  5,  7,  9  and  10. 

Even  though  the  bacteria  destroying  action  of  ozone 

c3  O 


upon  water  is  so  considerable,  still  it  is  not  to  be  avoided 
that  some  bacteria  survive.  This  is  owing  to  the  greater 
resistance  of  certain  bacteria;  still  the  oxidation  coefficient 
of  the  water  is  to  be  taken  into  account  as  well.  It  would 
be  unreasonable  to  expect  a  water  ozonizing  installation 
always  to  supply  water  perfectly  free  from  bacteria;  this  has 
not  been  obtained  by  any  of  the  central  water  purifying 
methods  now  known.  Nor  is  this  necessary  from  a  hygienic 
point  of  view ;  in  the  case  of  sand  filtration,  the  method  gen¬ 
erally  applied  for  the  purifying  of  surface  water,  a  decrease 
of  the  number  of  bacteria  to  ioo  per  cubic  centimeter  is  con¬ 
sidered  sufficient.  This  object  is  reached  to  perfection  with 
the  ozone  system,  for  it  has  been  proved  to  he  possible  to 
reduce  the  number  of  83,700-86,800  bacteria  in  Spree  water 
roughly  filtered  through  a  Kroehnke  filter  in  order  to  re¬ 
move  suspended  matter  to  20-28.  It  may  be  emphasized  that 
the  water  was  taken  from  the  Spree  below  Berlin,  after  it  had 
been  exposed  to  many  forms  of  contamination  on  its  course 
through  this  city.  When  the  ozone  method  is  employed — as 
well  as  in  the  case  of  sand  filtration — the  most  favorable 
conditions  of  the  “raw”  water  will  of  course  be  preferred, 
and  even  on  esthetical  grounds  the  pumping  station  will  not 
be  established  below  a  city ;  here  it  was  done  only  by  way 
of  experiment. 

By  sand  filtration  the  reduction  of  the  number  of  bac¬ 
teria  is  brought  about  mechanically ;  the  ozone  method  does 
this  chemically.  Experience  shows  that  sand  filtration  is  so 
efficacious  that  if  the  filter  is  properly  attended  to  the  danger 
of  infection  by  purified  water  is  reduced  to  an  allowable  mini¬ 
mum.  Still  C.  Fraenkel  and  C.  Piefke  have  proved  that 
under  certain  circumstances  pathogenic  micro-organisms 
pass  through  the  filter;  all  the  same  many  years’  experience 
has  shown  that  the  use  of  water  purified  by  sand  filtration 
cannot  be  objected  to. 

As  regards  the  ozone  methods,  the  behavior  of  patho¬ 
genic  micro-organisms  has  still  to  be  ascertained,  as  it  has 
been  proved  that  bacteria  with  greater  resisting  capacity 


32 


were  not  attacked  under  certain  circumstances.  Especially 
the  cholera  and  the  typhus  bacillus  are  to  be  considered  here 
as  being  causes  of  infection.  In  order  to  make  preliminary 
researches  experiments  were  made  in  the  laboratory  with  a 
small  apparatus  of  the  same  construction  as  those  in  the 
station.  In  order  to  render  the  capacity  of  this  laboratory 
apparatus  comparable  with  those  at  Martinikenfeld,  the 
supply  of  air  and  water  was  arranged  in  such  a  way  as  to 
bring  about  the  same  reduction  in  the  number  of  bacteria  in  a 
mixture  of  Spree  and  waterworks  water  in  equal  proportions 
as  was  ascertained  in  the  experimenting  station.  With  this 
apparatus  water  was  treated  containing  cholera  and  typhus 
bacteria  (for  the  sake  of  comparison  coli  bacteria  were  also 
employed),  obtained  from  1-3  days’  old  agar  cultures  in  ster¬ 
ilized  Spree  water  at  30°  or  in  a  mixture  of  this  water  with 
equal  parts  of  waterworks  water ;  mixtures  of  water  were 
employed  to  obtain  various  oxidation  coefficients.  The  bac¬ 
teria  in  question  were  introduced  in  such  great  quantities  that 
numbers  of  germs  were  obtained  as  never  occur  in  ordinary 
impure  water;  this  was  done  partly  to  force  the  experiment, 
partly  with  regard  to  the  fact  that  the  action  of  ozone  is 
influenced  by  the  number  of  germs  and  the  oxidability.  Be¬ 
fore  and  after  the  ozonization  two  gelatine  plates  were  pre¬ 
pared  with  the  water  each  time ;  the  former  were  counted 
after  two,  the  latter  after  ten  days.  The  results  were  as 
follows : 


a.  Bac.  Cholera  in  Spree  Water,  16,350  per  Cubic  Centimeter.  Incuba¬ 
tion  1  day  at  30°C. 


M  ill  igram  of  Ozone 
per  Liter  of  Air 

Oxydisability  Milligram  of  Oxygen 
Per  Liter 

Reduction  in  Or¬ 
ganic  Matter 

Number  of  Bac¬ 
teria  after  Ozo¬ 
nization 

Before 

Ozonization 

After 

Ozonization 

5-49 

7.92 

6.88 

I.04 

O 

4-53 

7.92 

6.96 

O.96 

O 

3-45 

7.92 

7.04 

0.88 

O 

2.88 

7.92 

7.12 

0.80 

O 

b.  Bac.  Cholera  in  Mixture  of  Spree  and  Main  Water,  i  :  i  17,850  per 
Cubic  Centimeter.  Incubation  1  day  at  30°C. 


5.19 

5.72 

5. °° 

0.72 

0 

4.41 

5-72 

4.88 

0.84 

0 

3-39 

5-72 

5-°4 

0.68 

0 

2.61 

5-72 

5-04 

0.68 

0 

c.  Bac.  Typhus  in  Spree  Water,  39,050  per  Cubic  Centimeter.  Incuba¬ 
tion  1  day  at  30°C. 


4  89 

8.40 

7-36 

1.04 

0 

4.20 

8.40 

7-52 

0.88 

0 

3-54 

8.40 

7.60 

0.8S 

0 

2.73 

S.40 

7.76 

0.64 

0 

d.  Bac.  Typhus  in  Mixture  of  Spree  and  Main  Water  1  :  1  31,400  per 
Cubic  Centimeter.  Incubation  3  days  at  30°C. 


5-3i 

5.60 

4.64 

0.96 

0 

4-56 

5.60 

4.72 

0.88 

0 

3-24 

5.60 

4.68 

0.92 

0 

2-49 

5.6° 

4.76 

0.84 

0 

e.  Bac. 

Coli  in  Spree  Water,  30,600  per  Cubic  Centimeter. 

5.28 

7.84 

6.88 

0.96 

0 

4-56 

7.S4 

6. 96 

0.88 

0 

3-42 

7.84 

6.88 

0.96 

0 

2.49 

7.84 

6.86 

0.88 

0 

f.  Bac.  Coli  in  Mixture  of  Spree  and  Main  Water,  1  :  1  36,000  per  Cubic 

Centimeter. 


5-3i 

5-84 

5  °4 

0.80 

0 

4.44 

5-84 

5-°4 

0.80 

0 

3-30 

5-84 

5.20 

0.64 

0 

2.64 

5-84 

5-24 

0.60 

0 

34 


Against  these  experiments  it  may  be  objected  that  they 
do  not  irrefutably  prove  the  destruction  of  the  bacteria,  as 
there  is  a  possibility  of  their  having  their  power  of  developing 
in  gelatine  through  the  action  of  ozone.  Therefore  two 
further  experiments  were  made  under  equal  circumstances 
as  regards  the  passage  of  air  and  water,  while  cholera  bacteria 
were  added  to  the  non-sterilized  water,  and  their  presence 
was  ascertained  by  the  “Enriching”  method  (by  a  peptone 
and  salt  solution).  The  results  were  as  follows: 


Kind  of  Water 

V 

£< 
w  <*_ 
u-  c 

E  $ 

Milligram  of  Oxygen 
Used  to  Oxidize  i 
Liter  of  Water 

ion  in  Or-  | 
Matter 

Total  Number  of  Bacte¬ 
ria  in  One  Cubic  Cen¬ 
timeter 

OX)  u 
^  D 

~  a 

Before 

Ozonization 

After 

Ozonization 

Reducti 

ganic 

Before 

Ozonization 

After 

Ozonization 

Spree  and  Main 
Water 

3  48 

6. 16 

5.28 

0.88 

45. >70 

6 

1  in  1 . 

3-54 

6.22 

5.28 

O.96 

43,890 

5 

These  two  experiments  with  the  small  apparatus  show 
the  same  result  as  was  observed  in  the  great  experimenting 
installation  at  Martinikenfeld,  viz:  a  decrease  of  oxidability 
to  the  number  of  germs  in  the  same  degree.  The  capacity  of 
the  small  apparatus  was  consequently  properly  adjusted  in 
comparison  with  the  large  installation. 

“During  the  experiments  six  samples  of  90  cubic  centi¬ 
meters  were  taken  from  the  ozonized  water,  and  twTo  from 
the  water  not  yet  treated,  and  then  submitted  to  the  enriching 
method  ;  in  the  latter  cholera  bacteria  could  be  detected,  in  the 
ozonized  water  they  had  been  destroyed.” 

After  these  two  preliminary  experiments  two  definitive 
ones  were  made  in  the  large  ozonizing  apparatus,  in  which 
cholera  or  typhus  bacteria  were  added  to  a  measured  quantity 
of  water.  Measures  were  taken  to  prevent  the  spreading  of 


35 


the  pathogenic  bacteria.  The  passage  of  the  ozonized  water 
from  the  “overrunning"  basin  to  the  reservoir  was  walled  up. 
The  connecting  tube  between  the  Kronke  filter  and  the 
basin  for  filtered  water  was  removed,  and  the  joint  screwed 
up ;  under  the  cock  A'  a  basin  containing  a  sublimate  solution 
was  placed  to  disinfect  any  water  that  might  drip  off.  The 
cock,  however,  proved  to  be  so  perfectly  tight,  that  no  water 
dripped  off.  The  quantity  of  water  to  be  infected  was  made 
so  great  that  it  could  be  contained  in  the  “overrunning’ ’ 
basin.  This  made  it  possible  to  sterilize  all  the  water  em¬ 
ployed  ;  this  was  done  by  making  it  boil  with  steam.  For  this 
purpose  a  pipe  was  laid  from  a  boiler  carrying  a  steam  pres¬ 
sure  of  io  atmospheres  to  the  “overrunning”  basin  and  the 
basin  for  filtered  water. 

The  arrangement  of  both  experiments  was  as  follows. 
First  the  basin  for  filtered  water  was  filled  with  i  cubic  meter 
of  water  (a  mixture  of  Spree  water  and  water  from  the 
waterworks).  For  the  cholera  experiment  it  was  used  with¬ 
out  any  further  preparation ;  for  the  typhus  experiment  it 
was  heated  to  the  boiling  point  by  means  of  steam,  in  order 
to  facilitate  any  difficult  typhus  diagnosis  through  the  de¬ 
struction  of  the  water  bacteria.  As  appeared  later  on,  the 
sterilization  of  the  water  was  not  perfect ;  perhaps  the  heat 
was  not  applied  for  a  sufficient  length  of  time;  certain  it  is 
that  during  the  cooling,  which  was  brought  about  by  leaving 
the  water  during  the  night  and  letting  a  piece  of  ice  float  in 
it,  germs  got  into  it. 

To  the  water  in  its  natural  condition  cholera  bacteria,  to 
the  boiled  water  typhus  bacilli  were  added.  Both  cultures 
(agar)  were  i  day  old  and  had  grown  at  370.  Cholera  bac¬ 
teria  were  added  in  such  a  quantity  that  accordingto estimate 
there  were  2000  in  every  cubic  centimeter;  as  to  the  number 
of  typhus  bacilli  the  determination  of  the  number  of  germs 
on  the  gelatine  plates  fixes  it  approximately.  In  order  that 


36 

the  pathogenic  bacteria  might  be  evenly  distributed,  the  water 
was  stirred  vigorously. 

In  the  meantime  the  ozone  apparatus  was  put  in  motion 
to  make  the  refrigerator  reach  its  maximum  drying  capacity 
and  to  obtain  the  desirable  concentration  for  ozone.  When 
the  apparatus  was  in  full  action,  the  infected  water  was 
passed  through  the  sterilizing  tower.  During  the  process 
samples  of  water  were  taken  to-  determine  the  oxidability  and 
the  number  of  germs,  and  others  for  the  direction  of  patho¬ 
genic  bacteria,  viz :  two  samples  before  treatment,  and  ten  of 
the  ozonized  water,  which  in  the  case  of  cholera  amounted 
to  180  cubic  centimeters,  in  the  case  of  typhus  to  ioo  cubic 
centimeters. 

When  the  experiment  was  finished,  the  basin  for  filtered 
water  was  filled  with  1.75  cubic  meters  of  water.  Then  steam 
from  the  boiler  was  conducted  into  this  basin  and  into  the 
“overrunning”  basin;  in  the  latter  the  steam  tube  was  next 
pushed  into  the  sterilizing  tower,  to  make  the  water  in  it 
boil ;  then  the  water  outside  in  the  “overrunning”  basin  was 
treated  in  the  same  way.  When  the  boiling  heat  had  been 
kept  up  in  both  basins  for  half  an  hour,  the  water  in  the  basin 
for  filtered  water,  while  kept  at  the  same  temperature,  was 
allowed  to  run  into  the  “overrunning”  basin,  and  in  order 
to  sterilize  the  connecting  tube  to  the  sterilizing  tower  the 
latter  was  rinsed  with  10  liters  of  alcohol.  In  the  “over¬ 
running"  basin  the  boiling  heat  was  kept  up  for  another  one- 
quarter  hour,  and  then  the  contents  were  allowed  to  run  into 
a  freshly  dug  sandhole  iW  meters  deep,  after  which  the  hole 
was  filled  up.  There  are  no  wells  in  the  vicinity  of  the  hole. 
In  order  to  sterilize  the  inside  of  the  tower,  ozonized  air  was 
passed  through  for  one  hour.  By  such  precautions  spreading 
of  the  bacteria  was  entirely  excluded.  It  may  be  stated  that 
during  these  two  experiments  the  production  of  ozone  was 
conducted  by  the  Engineer  Friberg;  the  infected  and  the 
ozonized  water  was  not  touched  bv  any  one  besides  ourselves. 


37 


Of  the  results  of  the  experiments  we  will  first  state  those 
bearing  upon  the  general  inquiry : 


Quantity  of  Water  per 
Hour  in  Cubic  Meters 

Quantity  of  Air  per 
Hour  in  Cubic  Meters 

Quantity  of  Ozone  Grams] 
per  Cubic  Meter 

Oxydisability  of  Water 

Expressed  in  Milligram 

of  Oxygen  Used  Up 

per  Liter  of  Water 

Oxydisability  of  Water 
Expressed  in  Milligram 
of  Oxygen  Used  Up 
per  Liter  of  Water 
After  Ozonization 

Reduction  in  Oxydisa¬ 

bility 

Total  Number  of  Bacte¬ 

ria  per  Cubic  Centi¬ 
meter  Before  Ozoniza¬ 
tion 

Total  No.  of  Bacteria 
per  Cubic  Centimeter 

After  Ozonization 

Number  of  Bacteria, 
Cholera  : 

1  Part  of  Spree  Water  . 

2  Parts  of  Main  Water  . 

7 

oc 

3-76 

4.64 

4.00 

O.64 

38,330 

8 

Number  of  Bacteria, 
Typhus  : 

2  Parts  of  Spree  Water  . 
i  Part  of  Main  Water  . 

7 

3§ 

3-79 

9-36 

8.l6 

1 .20 

16,590 

9.2 

Both  experiments  proceeded  quite  regularly;  they  had 
the  same  result  as  previous  ones,  viz :  a  decrease  of  oxida- 
bility  and  a  considerable  lessening:  of  the  number  of  perms 
in  the  water.  It  is  specially  remarkable  that  in  the  typhus 
experiment  there  was  such  a  high  oxidation  coefficient  as  had 
never  before  been  observed.  This  makes  the  experiment  all 
the  more  important,  as  the  number  of  germs,  too,  though 
smaller  than  that  in  the  cholera  experiment,  cannot  be  called 
small. 

The  samples  taken  for  the  detection  of  pathogenic  germs 
underwent  a  further  treatment.  Those  obtained  from  the 
cholera  experiment  were,  after  the  addition  of  pepton  and 
salt,  treated  by  the  “enriching"  method.  Some  of  the  “en¬ 
riched"  water  was  spread  on  agar  plates.  From  these  the 
colonies  suspected  to  consist  of  cholera  bacilli  were  removed 
by  oculation  for  further  treatment  by  gelatine  plates,  cholera 
red  reaction  being  made  use  of.  The  original  cholera  pure 
culture  with  which  the  water  had  been  infected  served  as  a 
basis  of  comparison.  The  detection  of  cholera  bacteria  in  the 
infected,  non-ozonized  water  was  possible  in  the  case  of  both 


samples  through  gelatine  culture  and  nitrosoindol  reaction. 
The  ten  samples  of  ozonized  water  were  treated  in  the  same 
way;  the  cholera  red  reaction,  however,  did  not  appear  in 
any  of  the  cultures  that  had  been  oculated  as  being  suspected 
of  containing  cholera  bacteria.  The  detection  of  typhus  bacilli 
was  also  introduced  by  an  “enrichment”  process,  viz:  by  the 
addition  of  bouillon  in  equal  quantities  of  the  water  to  be 
examined,  and  by  leaving  the  samples  for  18  hours  in  a  tem¬ 
perature  of  370  ;  after  this  some  was  spread  out  on  agar 
plates.  Out  of  the  typhus-like  cultures  agar  pure  cultures 
were  prepared,  and  these  were  composed  with  the  original 
typhus  culture  which  had  served  to  infect  the  water,  as  well 
as  with  a  pure  culture  of  bacteria  coli  commune  by  the  usual 
methods  of  typhus  diagnostics.  From  the  infected,  noil- 
ozonized  water  cultures  were  obtained,  which  in  colored  prep¬ 
arations,  in  suspended  drops,  by  their  growing  on  gelatine, 
agar  and  potatoes,  by  their  behavior  in  sterile  milk,  grape- 
sugar  solution,  litmus  and  Maassen’s  non-albuminous  culture 
fluid,  and  especially  through  R.  Pfeiffer's  immunity  reaction 
proved  to  be  typhus  bacilli.  On  the  other  hand,  the  26  pure 
cultures  (suspected  to  be  typhus  bacilli)  obtained  from  agar 
plates  out  of  ozonized  water,  proved  on  the  above  methods 
being  applied,  not  to  be  typhus  bacilli. 

“ These  two  experiments,  therefore ,  have  proved  that  by 
the  treatment  of  water  with  ozone  in  an  installation  like  the 
one  at  Martinikenfeld  the  bacteria  of  cholera  and  typhus  are 
destroyed.  This  result  is  confirmed  particularly  by  the  fact 
that  generally  speaking  typhus  bacilli  with  a  greater  power  of 
resistance,  in  spite  of  the  high  oxidability  of  the  water,  were 
destroved  as  surely  as  the  less  resistant  cholera  bacteria.” 

The  Result  of  the  Chemical  and  the  Physical  Examination 

It  must  be  required  of  any  method  that  is  to  make  any 
kind  of  water,  subterraneous  or  surface  water,  fit  for  use,  that 
the  injurious  ingredients  of  the  water  are  removed  or  reduced 
to  an  allowable  minimum,  that  the  dissolved  substances  which 


39 


we  consider  an  advantage  in  good  drinking  water,  are  not 
appreciably  changed,  and  that  no  foreign  substances  which 
have  an  injurious  influence  upon  water  used  in  food  or  as  a 
beverage,  are  added  to  the  same. 

In  what  manner  the  ingredients  that  are  not  dissolved 
are  influenced  by  the  ozone  process,  has  already  been  shown. 
The  visible  suspended  matter  is  removed  by  the  Kronke  filter, 
the  bacteria  are  with  the  exception  of  a  few,  destroyed  by  the 
action  of  ozone.  It  is  true,  it  has  not  been  proved  that  the 
cell  substance  of  the  dead  bacteria  is  completely  destroyed 
by  oxidation ;  still  this  amount  of  organic  matter  even  in 
water  that  is  very  rich  in  bacteria,  is  of  no  importance  what¬ 
ever  on  account  of  its  small  quantity.  As  to  the  influence  on 
dissolved  substances  the  chemical  analysis  of  the  water  gives 
the  desired  information ;  the  values  obtained  varied  between 
the  following  limits  :  I  liter  of  water  contained  milligrams  : 


Solid  Matter 

1 

Organic  Mattel 
(Oxygen) 

Ammonia 

Nitrous 

Acid 

Nitric  Acid 

Filtered  Spree 

Water  .  181.4-204.2 

6. 16-7. 12 

0.2-0. 3 

O 

0  to  trace 

Mixed  Water  232.8-330.0 

4.24-6.  16 

Trace  to  0  24 

O 

0  to  trace 

Ozoniz’d  W’t’r  181.2-330.0 

3-44-5-44 

1 

“  “  0.24 

O 

0  to  trace 

The  residue  figures  show  that  the  weight  of  the  dis¬ 
solved,  non-volatile  ingredients  of  the  water  has  not  been 
altered  by  the  action  of  ozone ;  they  vary  within  the  same 
limits  in  the  ozonized  water  as  in  Spree  and  mixed  water.  On 
the  other  hand  a  considerable  decrease  of  oxidable  substances 
has  taken  place ;  this  means  an  improvement  of  the  water. 
Taking  the  great  oxidizing  power  of  ozone  into  considera¬ 
tion,  it  must  cause  surprise  that  the  nitrogen  compounds  have 
been  influenced  so  little ;  it  might  at  least  be  expected  that  free 
ammonia  would  be  oxidized  into  nitric  acid.  Special  experi¬ 
ments  throw  light  on  this  point;  they  were  executed  with  the 
small  laboratory  apparatus;  solutions  of  various  concentra¬ 
tions  in  distilled  water  being  used. 


40 


Froehlich  had  already  shown  on  former  occasions,  that 
in  air  being  ozonized  small  quantities  of  nitrous  and  nitric 
acid — depending  on  circumstances — are  formed  from  the 
nitrogen.  This  is  accounted  for  by  the  fact  that  on  an 
electric  spark  passing  through  nitrogen  and  oxygen  nitric 
acid  is  obtained.  By  preliminary  experiments  it  was  possible 
to  ascertain  that  in  the  ozone  apparatus  a  small  percentage 
of  the  atmospherical  nitrogen  was  changed  into  nitric  acid ; 
lower  stages  of  oxidation,  especially  nitrous  acid,  did  not 
come  into  play.  The  result  obtained  was  as  follows  : 


'ime  taken  for 
Experiments 
in  Seconds 

Quantity  of  Air 
in  Liters 

Quantity  of  Ozone 
in  Milligram  per 
Liter 

Total  Quantity  of  Total  Quantity 
Ozone  IVi  illigram  of  Nitric  Acid 

455 

20 

3.00 

60.O  7.28 

540 

20 

3-96 

79.2  8.78 

490 

20 

8.4 

168.0  16.80 

230 

IO 

IO.44 

IO4.4  12.19 

In  order  to  obtain  a  clear  idea  of  the  action  of  ozone 
upon  the  ammonia  present  in  the  water,  the  nitric  acid  given 
off  by  the  air  was  extracted  from  the  ozone  by  means  of  con¬ 
centrated  sodium  lye.  The  formation  of  nitric  acid  in  water 
was  so  insignificant  in  these  experiments,  that  a  quantitative 
determination  was  not  worth  while;  only  the  shades  of  blue 
of  diphenylamine-sulphuric  acid  could  be  fixed.  In  the  table 
below  the  presence  of  nitric  acid  is  indicated  as  follows : 


By  o 


+  + 

H — I — b 
+  +  + 


no  trace, 
hardly  a  trace, 
very  slight  trace, 
slight  trace, 
a  trace. 


4  1 


The  result  was  as  follows : 


Free  Ammonia 


t/3  W 

v  S 

.£ 

ES 


s 

a 

u 

<D 

cx 


Milligram  of  Ammonia  per  Liter  of  Water 


±2  j-h 

c  <u 

a;  n_. 

< 

O 

6  0 

o  3 

</) 

u 

5d  S 

4  ^ 

<u 

5 

10 

20 

3° 

40 

5° 

IOO 

u 

40 

2 

2-5 

0 

0 

0 

0 

H — b 

-f  4- 

H — 1 — b 

40 

2 

4.0 

0 

0 

-j- 

4- 

b — 1 — b 

+  +  +  ' 

H — 1  b 

40 

2 

5-5 

0 

+ 

H - 1 - b 

H — 1 — b 

+  T  +  + 

+  +  +  + 

4 — 1 — i  b 

40 

2 

10.5 

1 

+  + 

+  +  +  + 

+  T  +  + 

+  +  +  + 

+  +  +  + 

b  +  tf 

Carbonate  of  Ammonium 


40 

2 

2-5 

0 

0 

0 

0 

0 

0 

0 

40 

2 

2.0 

0 

0 

0 

0 

0 

0 

0 

40 

2 

5-5 

0 

0 

0 

0 

0 

0 

0 

40 

2 

10.0 

0 

0 

0 

0 

0 

0 

0 

Chloride  of  Ammonium 


40 

2 

2.5 

0 

0 

0 

0 

0 

0 

0 

40 

2 

4.0 

0 

0 

0 

0 

0 

0 

0 

40 

2 

5-5 

0 

0 

0 

0 

0 

0 

0 

40 

2 

10.0 

0 

0 

0 

0 

0 

t 

0 

O 

Free  ammonia,  therefore  was  oxidized  only  when 
strongly  concentrated  or  when  the  percentage  of  ozone  was 
high,  and  even  then  only  in  a  slight  measure  ;  in  a  compound 
form  as  a  carbonate  or  as  a  chloride,  ammonia  was  not  influ¬ 
enced  at  all. 


42 


Nitric  acid,  both  when  free  and  in  a  compound,  behaved 
•differently.  The  experiments  yielded  the  following  results : 


As  Free  Nitrous  Acid  Per  Cent.  Oxidized  to  Nitric  Acid 


Cubic  Centime¬ 
ter  of  Water 
per  Minute 

Liters  of  Air 
per  Minute 

Milligram  of 
Ozone  per 
Liter  of 

Air 

Milligram  of  Nitrous  Acid  per  Liter 

of  Water 

5 

10 

20 

50 

50 

7 

J> 

2.30 

100 

60 

45 

20 

50 

3 

3*50 

100 

75 

5° 

3° 

50 

7 

j 

4-3° 

100 

80 

55 

35 

50 

7 

d) 

6.00 

100 

100 

75 

45 

Combined  to  Sodium  Per  Cent.  Oxidized  to  Nitric  Acid 


5o 

3 

2.80 

100 

95 

85 

5o 

3 

3-5° 

100 

1 00 

94 

5o 

3 

4-3° 

100 

100 

100 

5o 

3 

6.00 

100 

100 

100 

Here  as  opposed  to  the  result  obtained  in  the  case  of 
ammonia,  it  is  to  be  observed,  that  the  oxidation  is  greater 
when  the  dilution  is  stronger.  Further  it  is  particularly 
striking,  that  of  the  nitric  acid  in  compound  from  a  greater 
quantity  is  oxidized  than  of  free  nitric  acid;  this  fact  is  ac¬ 
counted  for  by  the  alkaline  reaction  of  the  nitrous  sodium. 
For  it  has  been  proved  that  the  action  of  ozone  upon  oxidable 
substances  is  more  powerful  in  the  case  of  alkaline,  than  in 
the  case  of  acid  and  of  neutral  reaction  of  water, 


j-. 

<v 


c 

G 


14 


Spree  Water 


Spree  and 
Main  Water 

I  in  I 


H3 


i-. 

O 

'"O  ^7 

03^ 

ii  >.  O 

a  . 


u 


ci 


o  5 

G  r± 

.2  c 

1  < 

<D  a 

(4'" 


o 

rj  rJ~l 
"u 

t— '  4—* 

x  « 

ftS  t 
d  <u 

Ck 

-Ml) 
cj  U  S 

s&o 


.tn 


Neutral 

Acid 

Alkaline 


Neutral 

Acid 

Alkaline 


Per  Minute 
Passed 

Milligram  of  Ozone  per 
Liter  of  Air 

Liters  of  Air 

Cubic  Centime¬ 
ter  of  Water 

7 

3 

50 

4-3 

7 

J 

50 

4-3 

7 

J> 

50 

4-3 

3 

50 

3-o 

7 

0 

5° 

3-o 

3 

5o 

3-o 

Milligram  of  Oxygen 
Required  to  Oxidize 
One  Liter  of  Water 

Organic 

•g 

I 

ci 

N 

•  —> 

N 

O 

N 

I  u 

<v  § 

O 

<u  c 

1)  N 

PQ 

•*-* 

c 

P4 

7.84 

6.64 

1.20 

7.84 

6.48 

I.36 

7.84 

5-36 

2.48 

6.24 

5.20 

I.04 

6.24 

5.20 

I.04 

6.24 

4.80 

1-44 

43 


The  reader  may  be  reminded  of  the  well-known  fact 
that  the  presence  of  nitrogen  compounds  in  water  is  ascer¬ 
tained  only  in  so  far  as  from  this  the  nature  of  the  contami¬ 
nation  can  be  inferred ;  from  a  physiological  point  of  view 
they  are,  in  the  quantities  in  which  they  are  usually  found  in 
drinking  water,  of  no  importance.  Hence  the  small  changes 
which  they  experience  through  the  action  of  ozone  are  of  no 
moment. 

In  reality  the  chemical  composition  of  water  is  only  in 
so  far  influenced  by  the  ozone  treatment,  that  ozone  is  dis¬ 
solved,  besides  decreasing  the  oxidability.  The  ozone,  how¬ 
ever,  is  reduced  to  ordinary  oxygen,  and  this  happens  the 
more  quickly,  the  proportion  as  the  oxidability  of  the  water 
before  treatment  was  higher;  as  a  rule  no  ozone  was  to  be 
detected  after  15-20  seconds.  Therefore  any  injurious  action 
of  ozone  upon  the  piping  is  excluded.  On  the  other  hand 
the  increase  of  oxygen  in  the  water  as  well  as  the  decrease  of 
oxidability  means  an  improvement. 

From  a  physical  point  of  view,  it  was  observed  that  the 
yellowish  color  of  river  water  entirely  disappeared;  the 
ozonized  water  was  always  colorless  and  clear.  A  foreign 
taste  or  smell  was  never  observed  in  it. 

In  order  to  have  a  guarantee,  that  the  ozone  installation 
always  acts  rightly  in  every  part,  the  engineer  Friberg  has 
invented  ingenious,  automatic  apparatus.  As  soon  as  dis¬ 
turbances  occur  in  the  supply  of  air  or  in  the  production  of 
ozone,  a  bell  signal  is  heard,  and  the  dropping  of  a  valve  on  a 
signal  board  indicates  the  cause  of  the  disturbance ;  at  the 
same  time  the  current  of  water  into  the  sterilizing  tower  is 
automatically  turned  off.  In  this  way  it  is  impossible  for 
water  that  has  not  been  subject  to  the  action  of  ozone  to  leave 
the  apparatus. 

The  results  of  our  experiments  may  be  summarized  as 
follows : 

( 1 )  By  treating  water  with  ozone  a  considerable  de¬ 
struction  of  bacteria  is  brought  about  ;  in  this  respect  the 


44 


ozone  method  is,  generally  speaking,  superior  to  the  removal 
of  bacteria  by  central  sand  filtering ; 

(2)  Cholera  and  typhus  bacteria  present  in  water  are 
destroyed  by  the  ozone  method ; 

(3)  Chemically  the  water  is  influenced  by  the  method 
only  in  so  far  as  a  decrease  of  oxidability  and  an  increase  of 
free  oxygen  takes  place ;  both  mean  an  improvement  of  the 
water; 

(4)  The  ozone  that  is  dissolved  in  the  water  during 
the  process,  is  technically  and  hygienically  of  no  conse¬ 
quence,  as  it  very  quickly  changes  into  oxygen ; 

(5)  The  method  improves  the  water  by  the  destruction 
of  coloring  matters,  and 

(6)  Owing  to  this  the  water  becomes  free  from  any 
foreign  taste  and  smell. 

Consequently  the  ozone  method  can  in  certain  cases- 
compete  with  other  known  and  tried  methods  of  central 
drinking  water  purification.  As  in  the  case  of  all  other 
methods  the  condition  of  the  raw  water  will  have  to  be  taken 
into  account,  and  especially  the  degree  of  oxidability  will 
have  to  be  paid  due  attention  to  when  ozone  is  employed. 

On  page  5  of  “  Public  Water  Supplies, ”  by  John  W. 
Hill,  Consulting  Engineer,  Philadelphia,  appears  the  fol¬ 
lowing  :  “  The  management  of  the  filters  and  mainten¬ 

ance  of  the  quality  of  water  supplied  to  the  chief  cities  of 
Holland  are  as  carefully  conducted  in  the  interests  of  the 
public  health  as  are  the  boilers  and  pumping  engines  oper¬ 
ated  in  the  interest  of  the  public  purse.  By  the  combined 
efforts  of  the  engineers,  chemists,  and  bacteriologists 
connected  with  the  waterworks  of  Holland,  the  water  is 
pumped  with  the  greatest  economy  of  fuel  and  is  con- 


45 


sumed  by  the  people  with  the  least  loss  of  life  from 
water-carried  diseases.” 

On  page  8  of  the  same  edition,  referring*  to  the  Rotter¬ 
dam  filter  plant,  he  says,  “Bacteriological  tests  are  made 
every  day.” 

On  page  139  Mr.  Hill  says:  “The  water  of  Rotterdam 
and  Berlin  is  filtered,  the  first  from  the  River  Maas,  and  the 
second  from  the  Rivers  Spree  and  Havel,  both  of  which  have 
received  sewage  and  surface  drainage  from  urban  and  rural 
territory  before  the  water  reaches  the  intakes  of  these 
works.” 

On  page  207,  under  the  head  of  Typhoid  Fever  Statis¬ 
tics,  “the  death  rate  per  hundred  thousand  of  Rotterdam, 
Holland,  is  among  the  very  lowest.” 

During  the  months  of  February  and  March,  and  up  to 
the  date  when  the  writer  left  Holland,  April  12,  the  follow¬ 
ing  notice  appeared  daily  in  the  Nieuwe  Rotterdamsche 
Courant : 


Kennisgeving. 


Burgemeester  en  Wethouders  van  Rotterdam, 
Overwegende,  dat  uit  de  resultaten  der  geregelde  con- 
trole  door  de  directie  der  gemeenteli jke  drinkwaterleiding 
op  het  ten  gebruike  af  te  leveren  water  geoefend,  bet  ver- 
moeden  is  voortgevloeid,  dat  bedoeld  water  niet  als  vol- 
komen  vrij  van  typhus-kiemen  is  te  beschouwen  en  dat  als 
gevolg  daarvan,  reeds  dadelijk  in  overleg  met  de  gezond- 
heidscommissie,  de  burgerij  bij  openbare  kennisgeving  tegen 
het  gebruik  van  ongekookt  water  en  ongekookte  melk  is 
gewaarschuwd ; 

Overwegende  dat  een  nader  onderzoek,  sedert  door 
professor  dr.  Eykman  te  Utrecht  ingesteld,  dit  vermoeden 
heeft  bevestigd ; 


46 


Gehoord  de  gezondheidscommissie  en  den  betrokken 
inspecteur  der  volksgezondheid ; 


besluiten : 


te  verklaren  dat,  onder  de  tegenwoordige  omstandig- 
heed,  het  gebruik  van  ongekookte  leidingwater  de  ingeze- 
tenen  aangevaar  blootstelt,  en  er  opnieuw  met  alien  ernst  op 
aan  te  dringen  dat,  terwijl  alles  wordt  in  het  werk  gesteld 
om  de  oorzaken  der  besmetting  weg  te  nemen,  voorshands 
ook  dit  drinkwater  niet  dan  gekookt  worde  gebruikt. 

Burgemeester  en  Wethouders  voornoemd, 

De  Secretaris,  De  Burgemeester, 

Heynsius.  s’Jacob. 

which,  translated  into  English,  reads  as  follows : 


Notice. 


The  Mayor  and  Councils  of  Rotterdam  considering 
that,  from  the  tests  results  obtained  by  the  regular  super¬ 
vision  of  the  city’s  water  supply,  it  is  suspected  that  the 
water  is  not  free  of  typhoid  germs,  and  in  consequence 
thereof  the  Board  of  Health  by  public  announcements 
promptly  warns  the  citizens  against  the  use  of  unboiled 
water  and  unboiled  milk. 

And  considering  a  later  investigation  made  by  Prof. 
Dr.  Eykman  of  Utrecht  has  confirmed  this  suspicion,  after 
consultation  with  the  Board  of  Health  and  the  Inspector. 

Resolved,  To  give  notice  that  under  present  conditions 
the  use  of  unboiled  water  exposes  the  citizens  to  danger,  and 
to  strongly  insist  to  not  use  this  drinking  water  unless  it  be 
boiled  first,  while  everything  is  being  done  to  eliminate  the 
cause  of  the  pollution. 


Heynsius, 

Secretary. 


THE  MAYOR  AND  COUNCILS, 

s,  Jacob, 


M  ay  or. 


47 


In  addition  to  this  the  city  was  liberally  placarded  with 
large  printed  notices  of  a  similar  nature,  warning  the  citizens 
against  the  use  of  water  or  milk  unless  first  boiled,  and 
recommending  the  washing  of  hands  in  previously  boiled 
water  before  taking  food. 

The  writer  visited  the  Waterworks  at  Rotterdam,  Hol¬ 
land,  on  Thursday,  February  u,  and  was  courteously  af¬ 
forded  by  Dr.  Van  't  Hoff  an  opportunity  to  inspect  the  filter 
system,  and  in  fact  every  part  of  the  plant,  and  in  an  inter¬ 
view  with  Dr.  Van  T  Hoff,  the  latter  admitted  that  his  con¬ 
fidence  in  the  reliability  of  sand  filtration  was  shaken,  and 
this  is  in  accord  with  what  Mr.  Hill  says  on  page  131  of  his 
same  work : 

“Some  writers  in  their  enthusiasm  have  declared  that 
sand  filters  properly  constructed  and  operated  will  furnish 
pure  water.  This  is  a  mistake.  No  filter  operated  upon 
a  practical  basis  has  ever  furnished  pure  water;  but  the  so- 
called  purified  water  is  so  much  superior  to  the  unfiltered 
water  that  it  will  meet  the  practical  requirements  of  cities 
and  communities  to-dav  and  ‘  when  the  time  is  reached 
that  the  people  demand  absolutely  pure  water,  the 
methods  for  furnishing  it  will  doubtless  be  forthcoming/ 
For  the  present,  and  as  a  practical  method  of  water  purifica¬ 
tion,  filtration  may  be  regarded  as  entitled  to  full  credit  at 
the  hands  of  city  officials  and  waterworks  managers.” 

“Filtration,  as  the  term  is  defined  and  generally  under¬ 
stood,  consists  of  an  interception  or  straining  out  from  a 
fluid  such  suspended  matter  as  is  larger  in  some  dimensions 
than  the  pores  of  the  filtering  medium.  The  action  is  sup¬ 
posed  to  be  purely  mechanical,  and  the  efficiency  of  a  filter 
will  be  measured  by  the  fineness  or  coarseness  of  the  filtering 
material.  The  filtration  of  water,  however,  demonstrates 
that  the  fineness  of  the  filtering  material  is  not  exactly  a 
measure  of  the  efficiency,  and  the  finest  or  smallest  grain  of 
sand  does  not  always  give  the  best  results. 


48 


“This  fact,  then,  would  naturally  suggest  that  the 
straining  action  is  only  a  part  of  the  work  accomplished  by 
the  filter ;  and  in  addition  to  the  interception  of  certain  sus¬ 
pended  matters  at  the  surface  of  the  sand-bed,  some  other 
forces  are  at  work  to  reduce  the  suspended  matter,  including 
the  bacteria,  in  the  water.  One  of  these  forces  is  now  known 
to  be  the  action  of  the  bacteria  on  the  organic  matter.  This 
is  called  the  biologic  action  of  the  filter. 

“The  bulk  of  the  suspended  matter,  including  the  bac¬ 
teria  in  water,  will  be  intercepted  at  the  surface  of  the  sand. 
Here  the  process  of  splitting  up  the  organic  matter  into  its 
nitrogenous  and  carbonaceous  elements  is  continually  going 
on ;  the  carbons  going  off  as  carbon  dioxides  and  other  gases, 
and  the  nitrogenous  matters  being  converted  info  nitrous  and 
nitric  acids,  which  in  turn  unite  with  the  bases  in  the  water, 
forming  nitrites  and  nitrates,  in  themselves  harmless  pro¬ 
ducts  of  bacterial  action. 

“This  biological  action  of  a  filter  is,  after  all,  its  most 
important  function.  The  simple  straining  process  of  a  bed 
of  sand  or  of  other  filtering*  material,  while  competent  to 
render  turbid  water  clear,  could  have  but  little  effect  upon  the 
bacteria,  because  many  of  these  are  so  small  in  some  dimen¬ 
sions  as  to  grow  .through  a  sand-bed  of  almost  any  prac¬ 
ticable  fineness.  The  action  of  the  organisms  in  the  water 
on  the  organic  matter  results  in  the  production  of  a  thin 
semigelatinous  film  over  and  around  the  grains  of  sand  in 
the  upper  layers  of  a  bed,  which  in  due  time  becomes  so  dense 
as  to  clog  it,  and  requires  a  high  head  to  force  the  desired 
amount  of  water  through  the  sand ;  whereupon  such  sand-bed 
is  temporarily  taken  out  of  service,  the  water  drawn  down 
some  distance  below  the  surface,  and  the  upper  fraction  of  an 
inch  of  the  sand  removed.  With  the  new  surface  of  sand 
exposed,  the  filter  is  ready  for  service  again. 

“When  the  water  is  drawn  off  a  filter  for  renewal  of  the 
surface  of  the  sand-bed,  two  important  events  occur.  One 
consists  of  the  paring  off  of  a  thin  layer  of  the  clogged  sand 


49 


mentioned  above;  and  the  other  of  a  complete  or  partial 
aeration  of  the  sand-bed,  by  means  of  which  the  nitrifying 
bacteria  in  the  bed  are  supplied  with  air  (oxygen),  without 
which,  according  to  the  authorities  who  have  especially 
studied  these  organisms,  the  nitrifying  bacteria  would  soon 
perish,  and  their  functions  in  the  reduction  of  nitrogenous 
organic  matter  to  nitrous  and  nitric  acids  be  lost. 

“All  sand  filters  are  therefore  intermittent  filters.  None 
work  continuously.  Each  time  the  water  is  drawn  below  the 
surface  of  the  sand-bed,  there  is  a  partial  aeration  of  the 
sand ;  and  when  the  water  is  drawn  off  entirely,  during  the 
operation  of  paring  away  the  upper  one-half  (J4)  inch  or  so 
of  dirty  sand,  the  bed  is  rested,  as  it  were,  and  complete 
aeration  occurs. 

“This  upper  dirty  layer  of  sand,  which  contains  inor¬ 
ganic  matter  intercepted  from  the  water,  and  the  products 
of  vital  activity  of  the  water  bacteria,  is  called  the  ‘Schmutz- 
decke’  by  Mr.  Piefke,  who,  the  author  believes,  was  the  first 
to  point  out  the  manner  in  which  the  semigelatinous  film  was 
formed,  and  how  it  consisted  of  intercepted  matter  in  suspen¬ 
sion,  and  organic  matter  in  process  of  destruction  by  bacterial 
agency.” 

And  further  on,  “The  ‘Schmutzdecke,’  or  film  of  inter¬ 
cepted  suspended  matter  and  products  of  bacterial  action,  is  a 
delicate  membrane  lacking  in  consistency,  and  easily  broken 
by  too  rapid  changes  of  pressure  (head)  on  the  sand-bed; 
and  when  broken  bad  results  are  liable  to  follow.  The  author 
cannot  do  better  than  quote  from  Mr.  Gill  upon  this  feature 
of  sand  filtration  : 

“  ‘Since  the  bacteria  are  liable  to  be  washed  downwards 
by  a  stream  of  greater  force  than  that  which  prevailed  when 
thev  came  into  contact  with  the  sand  grains,  it  is  of  the 
utmost  importance  to  avoid  an  increase  of  speed,  especially  a 
sudden  increase.  Mechanical  arrangements  must  he  adopted 
to  prevent  this,  and  it  must  be  impossible  that  any  filter  in 
action  can  in  any  way  effect  the  yield  of  the  nei  ghi  coring 


filter.  The  chief  cleansing'  action  takes  place  in  the  mud  de¬ 
posit  on  the  surface  of  the  sand,  and  in  the  sand  immediately 
at  the  surface.  In  this  region  the  coating*  of  deposit  is  soft, 
and  with  its  dense  population  requires  careful  and  tender 
treatment  to  avoid  squeezing*  out  the  bacteria  by  undue  pres¬ 
sure.  It  is  obvious  that  as  soon  as  an  appreciable  deposit  has 
taken  place  on  the  sand  surface,  any  increase  of  “head”  must 
be  chiefly  caused  by  the  layer  of  this  deposit.  If  the  sand  be¬ 
neath  is  not  absolutely  homogeneous,  as  it  cannot  be,  any  in¬ 
crease  of  pressure  may  cause  a  depression  and  a  tearing  of  the 
mud-skin  on  the  less  dense  parts  of  the  surface  of  the  sand. 
Through  such  a  rupture  the  bacteria  are  at  once  washed  by 
the  increased  local  current  which  ensues  into  the  sand  be¬ 
neath,  and  may  be  carried  through  the  entire  layer.  Yet  a 
gradual  increase  of  pressure  must  of  necessity  take  place, 
when  the  yield  is  to  be  constant,  in  order  to  overcome  the  in¬ 
creasing  friction  of  the  passage  of  the  water  through  the  fil¬ 
tering  medium,  in  proportion  as  its  interstices  become  grad¬ 
ually  closed  by  the  deposit.  Nor  is  such  increase,  if  gradual, 
injurious,  provided  certain  limits  be  not  exceeded.” 

The  efficiency  of  the  sand  filter  bed  then  is  dependable 
upon  its  biological  action  in  which  the  Schmutzdecke  plays 
the  most  important  part,  yet  it  is  this  Schmutzdecke  which 
interferes  with  the  flow  or  capacity  of  the  filter,  and  for  this 
reason  requires  to  be  removed  whenever  the  capacity  has 
been  reduced  to  a  point  beyond  which  the  filter  bed  becomes 
practically  useless. 


In  the  D cut sch  Revue,  of  May,  1903,  edited  by  Richard 
Fleischer,  an  article  by  Dr.  H.  J.  Van  T  Hoff  appears,  en¬ 
titled 

Water  Supply  of  Cities. 

OZONE  AND  ITS  APPLICATION  TO  THE  PURIFYING  OF 

DRINKING  WATER. 

from  which  I  translate  the  following : 

“Experts  in  matters  of  hygiene  and  business  men  agree 
that  dune  water  and  deep  well  water  may  be  considered  as 
ranking  first  in  quality  for  drinking  purposes,  but  it  is  not 
possible  for  every  community  to  command  either  of  these 
sources.  In  that  case,  there  is  nothing  left  to  do  but  to  make 
use  of  surface  water,  although  this  may  contain  more  or  less 
infected  substances.  The  science  of  filtration  has  lately 
reached  such  a  high  point  of  perfection  that  we  may  be  per¬ 
mitted  to  say  that  a  thoroughly  supervised  waterwork  can 
furnish  the  very  best  results,  and  that  more  epidemics  have 
their  source  in  ground  water  than  in  well  controlled  or  super¬ 
vised  surface  water  ;  but  with  all  this  sand  filtration  is  a  deli¬ 
cate  job,  and  surely  none  will  ever  dare  to  hope  that  through 
it  perfect  sterilization  can  be  readied.  When,  as  for  instance, 
at  Rotterdam,  the  reduction  is  from  99%  to  99^2  %  of  the 
bacteria  which  the  sand  filter  holds  back,  this  result  may 
well  be  considered  as  the  highest  possible  obtainable  and 
is  hygienically  considered  very  assuring.  But  it  will  not  do 
to  close  our  eyes  to  every  improvement  which  is  offered, 
and  every  one  who  handles  the  question  of  sand  filtration 
should  embrace  every  means  obtainable  to  further  perfect  or 
aid  sand  filtration. 

“For  the  sterilization  of  water  numerous  chemical  means 
have  been  recommended,  none  of  which  were  worth  consider¬ 
ing  in  connection  with  the  technical  question  of  water  supply. 
They  were  either  too  dear  or  they  changed  the  quality  of 
the  water  by  introducing  foreign  substances,  which  interfered 
with  the  consumption.  But  of  all  these  means  ozone  has 


52 


lately  assumed  a  prominent  position,  and  has  been  transferred 
from  the  laboratory  to  use  in  practice,  hence,  ozone  water¬ 
works  are  successful  in  improving  on  sand  filtration.  If  by 
the  use  of  ozone  complete  sterilization  is  not  reached  its  ap¬ 
plication  reduces  the  bacteria  proportion  still  further. 

“As  bacteriologist  of  the  waterworks  of  Rotterdam,  I 
have  gladly  accepted  an  opportunity  to  interest  myself  with 
this  question,  and  I  am  pleased  to  give  my  experience  in  this 
direction  to  the  public,  believing  that  the  water  supply  is  one 
of  the  most  important  problems  of  the  present  day,  and  is  of 
interest  to  each  and  every  one.  In  the  year  1785" — The 
article  then  goes  on  with  a  resume  of  the  discovery  of  ozone, 
and  then  describes  the  systems  of  Marmier,  Tyndall  and 
Siemens  &  Halske,  and  in  each  case  places  stress  upon  the 
dielectrodes  (such  as  glass)  used,  and  finally,  on  page  4, 
describes  the 

System,  Vosmaer 

“On  this  system  a  waterworks  was  erected  at  Schiedam 
and  later  in  Nieuwersluis  near  Amsterdam,  which  latter  one 
is  now  in  daily  use.  I  was  pleased,  inasmuch  as  I  am  so 
interested  in  the  question  of  ozonizing  of  water,  to  have  the 
company  turn  the  technical  control  over  to  me,  and  with 
this  I  have  occupied  myself  lately. 

“These  electrical  experts  work  with  a  potential  of  one 
hundred  volts  and  a  current  strength  of  20  amperes.  This 
current  is  changed  into  10,000  volts  and  .2  amperes,  or  say 
2000  volt-amperes.  The  current  changes  one  hundred  times 
in  a  second,  or  100  alternations.  The  air  is  dried  through 
chloride  calcium  and  afterwards  measured.  One  pole  of  the 
ozonizer  is  connected  with  a  secondary  high  tension  current; 
the  other  grounded.  One  pole  consists  of  a  row  of  points 
which  lie  opposite  the  other  pole. 

“The  method  of  connecting  and  the  apparatus  employed 
in  connection  therewith  prevents  any  arc  formation.  No 
dielectric  is  used,  and  concentration  of  from  three  to  four 


milligrams  of  ozone  per  liter  of  air  is  obtained.  The  water 
supply  is  from  the  Vecht  and  is  of  a  very  bad  quality,  and  is 
filtered  only  through  a  rapid  mechanical  filter  (System 
Kronke)  to  remove  the  heavier  particles.  The  sterilizer 
works  as  counter-current  apparatus  and  delivers  from  20  to 
30  cubic  meters  of  water  per  hour,  etc. 

“One  thing  is  certain  that  the  great  advantages  of  ozon- 
ization  are  readily  apparent.  The  idea  of  maintaining  a 
good  product,  allowing  the  use  of  any  water  as  source  of  sup¬ 
ply,  let  alone  the  smaller  ground  space  for  installation 
required,  besides  the  certainty  of  an  absence  of  all  pathogenic 
bacteria,  is  so  important  that  sand  filtration,  no  matter  how 
well  it  may  work,  and  how  careful  the  supervision  of  it 
be,  in  my  opinion,  must  he  inferior  to  ozonization,  and  I  be¬ 
lieve  the  time  is  not  far  off  when  one  of  the  weightiest 
questions  in  the  field  of  hygiene  will  he  fully  solved.  Even 
if  complete  sterilization  he  not  continuously  maintained,  in 
some  tests  made  recently  hv  Proskauer  and  Schuder  in  Wies¬ 
baden,  where  the  bacteria  in  raw  water  was  artificially 
increased  by  40,000  colonies  per  cubic  centimeter,  the  reduc¬ 
tion  was  very  great,  since  in  the  ozonized  water  only  16 
bacteria  remained. 

“(Signed)  Dr.  H.  J.  van  "t  Hoff.” 
“Water  Works,  Rotterdam,  1903.” 

HOW  OZONE  MAY  BE  MADE: 

Ozone  may  he  made  by  chemical  means  and  by  electrical 
means.  Slow  combination  of  phosphorous  causes  ozone  to  he 
generated,  or  the  heating  of  silver  or  gold  oxides  produces 
ozone  in  trifling  quantities,  hut  neither  these  nor  any  other 
chemical  method  has  any  commercial  value  inasmuch  as 
ozone  can  he  made  by  simple  methods  electrically. 

One  way  is  to  decompose  water  which  has  been  strongly 
acidulated  by  electrolysis,  the  oxygen  liberated  at  the  positive 
electrode  contains  ozone,  hut  the  best  and  most  practical  way 


54 


is  to  polymerize  the  oxygen  contained  in  the  air  by  means  of 
an  electrical  discharge,  viz :  the  so-called  silent,  dark  or  brush 
discharge. 

When  high  tension  electricity  is  allowed  to  flow  from 
discharges  in  such  a  way  that  neither  a  spark  nor  a  voltaic 
arc  but  only  a  brush  discharge  is  obtained,  then  oxygen, 
whether  pure,  or  as  in  atmospheric  air  mixed  with  nitrogen, 
will  be  partly  changed  into  ozone,  and  thus  evidently  the  only 
thing  required  is  to  provide  means  for  obtaining  such  brush 
discharge,  and  no  other,  inasmuch  as  sparks,  though  they  do 
no  harm,  will  do  no  good  either,  and  the  voltaic  arc  must  be 
implicitly  avoided,  or  rather  made  impossible,  since  its  great 
heat  is  destructive  of  any  apparatus  employed. 


ELECTRIC  DISCHARGES: 

A  spark  (Figure  i),  well  known  in  appearance  because 
lightning  is  a  spark  discharge,  is  a  white  colored  zigzag,  loud 
snapping,  oscillatory  discharge.  Figure  2  is  a  photograph 
taken  of  ten  consecutive  sparks  from  a  static  machine  as 
shown  in  Figure  1.  This  discharge  is  useless  for  ozone 
making. 

A  Rhumkorf  induction  coil  when  operated  by  a  high 
frequency  interrupter,  such  as  the  Wehnelt  or  rotary  mer¬ 
cury,  produces  a  spark  mixed  with  the  violet  brush  discharge 
(Figure  3).  A  voltaic  arc,  well  known  in  its  form  in  the 
ordinary  arc  lamp,  furnishes  the  greatest  obstacle,  because  its 
intense  heat  melts  anything  known. 

Figure  4  is  a  reproduction  from  a  small  arc  from  an 
alternating  current  transformer.  It  may  assume  a  length  of 
several  feet ;  is  characterized  by  a  humming  sound — a  flame¬ 
like  shape  ever  changing,  and,  as  has  already  been  said,  pro¬ 
duces  an  intense  heat.  It  is  a  continuous  discharge  of  great 
current  strength,  and  hence,  of  great  danger  to  the  life  of 
metallic  discharges  and  apparatus. 


Fig.  2 


Fig.  6 


Fig.  4 


Fig. 


Quite  different  from  all  these  previously  named  is  the 
brush  discharge — characterized  by  a  dark  blue  violet  color. 
It  is  a  convective  discharge  uni-directional  from  positive  to 
negative.  Figure  5  is  a  photographic  reproduction  of  a  true 
positive  brush  discharge,  while  Figure  6  is  the  same  of  a 
negative  discharge — evidently  of  quite  another  character. 
Figure  7  is  a  photograph  of  the  word  “Ozone"  in  brush  dis¬ 
charge  (From  a  high  tension  transformer  of  ordinary  fre¬ 
quency).  It  is  this  particular  kind  of  discharge  which 
causes  ozone  to  be  generated.  There  are  five  essentially 
different  systems  of  producing  this  silent  electrical  discharge. 
The  first  system  is  based  upon  the  principle  that  if  some 
solid  dielectric  (non-conductor)  such  as  glass  or  mica,  etc., 
be  placed  between  the  electrodes  or  discharger,  which  are 
separated  by  an  air  gap,  between  which  high  potential  dif¬ 
ferences  are  kept  up,  neither  the  spark  nor  the  arc  discharge 
can  take  place,  and  the  result  is  that  a  beautiful  silent  dis¬ 
charge  is  maintainable  without  any  interruptions  as  long  as 
the  dielectric  holds. 

Now  for  the  purpose  of  ozone  making  nothing  of  an 
organic  character,  such  as  hard  rubber,  vulcanite,  or  the  like, 
can  be  used,  and  of  all  known  non-conductors  mica,  glass 
and  china  are  the  only  ones  available.  Mica,  however,  does 
not  stand  a  high  dielectric  stress.  China  and  also  enamel 
are  no  good  at  all,  and  thus  glass  only  is  left  over.  But, 
however  excellent  glass  may  be,  its  treacherous  behavior 
under  electric  stress  is  well  known,  and  the  drawback  against 
its  use  is  its  fragility,  because  suppose  an  ozone  apparatus  at 
work;  a  beautiful  intense  brush  discharge  takes  place  be¬ 
tween  one  metallic  coating  and  the  other;  when  suddenly, 
without  known  cause,  a  spot  in  the  glass  (say  an  air  bubble, 
or  some  other  unhomogeneity)  becomes  a  little  more  heated 
than  the  rest.  As  soon  as  this  takes  place  the  glass  becomes 
somewhat  conductive ;  a  little  more  current  passes  there 
which  causes  still  more  heat,  and  after  a  while — it  may  be 
a  minute;  it  may  be  an  hour  or  a  day — that  particular 


59 


warm  spot  becomes  so  heated  that  it  becomes  a  real  con¬ 
ductor  (which  occurs  at  400°  C.)  when  all  the  current 
strength  at  once  concentrates  there  and  a  breakdown  is  the 
inevitable  result.  A  voltaic  arc  is  established  and  unless 
immediately  looked  after  the  apparatus  is  soon  ruined.  So 
great  has  been  this  drawback  that  until  lately  ozone  has 
never  been  able  to  make  its  way  into  practical  use,  because 
glass  apparatus,  with  the  ever  present  danger  of  break¬ 
downs,  was  objectionable  to  practical  men  for  use  on  a 
large  scale.  It  was  in  1892  that  the  great  firm  of  Siemens 
&  Halske,  having  at  that  time  discovered  the  remarkable 
bactericide  power  of  ozone  for  potable  water,  promised  to 
bring  out,  a  commercial  ozonizing  apparatus  (see  Elektro 
Technische  Zeitschrift,  1891,  Heft  26,  p.  340).  Nearly  ten 
years  elapsed  before  they  did  bring  out  an  ozonizer,  but 
not  differing  in  principle  from  the  one  they  had  in  1891 — 
the  same  thing  again,  viz :  high  potential  electrodes  separ¬ 
ated  by  glass.  In  1901  they  came  out  with  an  apparatus 
built  up  of  mirror  glass  plates,  which  they  claimed  to  be  the 
very  best  arrangement  for  technical  use.  (See  Journal  fur 
G asb el euch tung  mid  Wasserversorgung,  1901,  Nos.  30  and 
31,  and  “die  Gesundheit  ”  1901,  No.  15)  ;  flat  glass  plates 
being,  according  to  their  publication,  superior  to  glass  tubes, 
and  thus  that  apparatus  a  great  improvement  on  those  form¬ 
erly  used.  One  year  later,  1902,  the  same  firm  erected  a 
large  ozone  plant  near  Wiesbaden,  but  “the  great  improve¬ 
ment"  was  not  employed,  and  they  returned  to  their  old 
tube  system  of  1891.  (S ee  “Gesundheit  ”  1902,  No.  19.) 

Though  glass  tubes  may  be  tested  beforehand  and  the 
objectionable  ones  culled  out,  still  there  always  remains  the 
fact  that  the  substance  called  glass  is  treacherous,  as  it  cannot 
withstand  the  ever-changing  great  electrical  stress  put  upon 
it,  and  hence  it  is  unreliable. 

It  is  not  worth  while  to  refer  to  other  systems  of  ozo- 
nizers  based  upon  the  use  of  glass,  inasmuch  as  they  are  all 
alike — untrustworthy — and  none  of  them  have  ever  been 


6o 


able  to  make  headway,  or  have  ever  been  put  to  practical  use. 
Credit,  however,  must  he  given  to  the  firm  of  Siemens  & 
Halske  in  that  they  found  a  way  to  somewhat  eliminate  the 
difficulty,  viz;  of  subdividing  the  plant  in  a  number  of  small 
units,  so  that  a  breakdown  of  one  unit  does  not  mean  entire 
stoppage.  All  apparatus  of  the  kind  referred  to  had  auto¬ 
matic  devices  for  cutting  out  the  current  in  case  of  a  break¬ 
down  of  a  glass  tube  (a  strip  of  blotting  paper  holding  a 
spring,  and  when  the  paper  gets  water  soaked  it  gives  away, 
releasing  the  spring  which  cuts  off  the  current).  Moreover 
the  glass  tubes  are  water  cooled  (with  water  of  6o°  C.)  and 
numberless  automatic  cutouts,  check  valves,  etc.,  are  pro¬ 
vided  to  prevent  great  mischief;  in  other  words,  reliance 
must  be  placed  upon  the  much  discussed  and  doubted  relia¬ 
bility  of  automatic  arrangements. 

Andreoli,  Abraham-Marmier,  Yost,  Yarnold,  Lamprey, 
Friedham,  and  all  the  others,  use  a  dielectric  and  hence  cope 
with  an  unreliable  quantity. 

The  second  system  (it  may  be  called  a  system  because  it 
differs  in  principle  from  the  others  and  not  merely  in  make) 
involved  the  use  of  high  frequency  current — sometimes 
called  Tesla  currents.  The  effect  of  high  frequency  currents 
on  the  character  of  electric  dischargers  to  obtain  brush  dis¬ 
charges  and  nothing  but  these,  i.  e.,  no  sparks  or  arcs  or 
difficulty  whatever,  is  marvelous.  No  dielectric  is  needed, 
but  the  system  of  high  frequency  currents  involves  difficul¬ 
ties  commercially  which  makes  it  prohibitive,  as  the  effi¬ 
ciency  electrically  considered  is  very  low,  i.  c.,  only  a  small 
part  of  the  energy  produced  is  converted  into  brush  dis¬ 
charge  ;  besides,  the  high  frequency  brush  discharge  gives 
very  little  ozone  when  compared  to  that  generated  by  the 
ordinary  brush  discharge. 

J  o 

The  third  system  is  that  of  Tyndall.  Tyndall  uses  no 
dielectric  whatever,  but  interposed  in  the  circuit  a  high 
resistance,  such  as  a  tube  filled  with  gylcerine  showing 
something  like  20,000,000  ohms  resistance.  Fie  starts  with 


ordinary  alternating  current  transforming  up  to  40,000  or 
60,000  volts,  leads  this  to  the  20,000,000  ohms  resistance 
and  then  to  the  dischargers  proper ;  these  being  made  of 
very  fine  platinum  wire  gauze  set  on  end  so  as  to  furnish 
many  fine  points. 

This  system  certainly  has  the  advantage  of  being  an 
improvement  on  the  former  systems,  but  has  the  disadvantage 
of  furnishing  a  very  poor  efficiency  in  ozone  yield ;  moreover 
it  cannot  be  worked  without  artificial  cooling  (down  to 
—  25 0  C. ),  and  requires  careful  attendance,  because  after  all 
the  high  resistance  does  not  prevent  arcs ;  it  only  prevents 
sparks. 

In  the  Vosmaer  system  there  are  no  solid  dieletrics 
between  dischargers,  neither  high  frequency  nor  high  resist¬ 
ances  nor  rotating  electrodes,  but  the  brush  discharge  is  pro¬ 
duced  by  using  sharp  pointed  dischargers  against  fiat  elec¬ 
trodes  and  the  voltaic  arc  by  a  special  way  of  connecting  up, 
is  absolutely  prevented.  (See  Figure  8.)  In  this  diagram, 
T  is  an  ordinary  step-up  transformer,  C  is  a  high  tension 
condenser,  L  is  a  high  tension  choking  coil,  and  O  is  the 
ozonizing  apparatus.  The  high  tension  alternating  cur¬ 
rent  from  T  is  shunted  by  the  condenser,  while  the  choking 
coil  is  in  series  with  the  line.  In  this  way  an  arc  dis¬ 
charge  at  O  is  an  absolute  impossibility.  The  ozonizing 
apparatus  per  sc  is  simplicity  itself.  There  are  no  moving 
parts ;  no  fragile  material  is  employed  and  no  cooling  what¬ 
ever  is  resorted  to.  The  ozonizer  consists  (Figure  9)  of  a 
number  of  tubes  put  together  something  like  a  feed  water 
heater.  In  each  tube,  d,  there  is  a  complete  set  of  dis¬ 
chargers,  viz:  one  fiat,  a,  and  one  pointed,  b,  (see  Figure 
10)  separated  from  each  other  at  a  fixed  distance  by  insul¬ 
ated  stems  and  forks,  c  (made  of  porcelain).  There  is 
nothing  out  of  the  ordinary  about  the  transformer  or  choke 
coil,  but  the  condenser  is  of  special  manufacture.  Its  general 
outline  is  shown  in  Figure  11,  and  if  made  with  care  it 
never  gives  rise  to  the  slightest  trouble  whatsoever. 


rs 

1 


66 


FI  means  the  rough  filter  from  which  the  water  by  means 
of  the  pump  Wp  gees  to  the  top  of  the  sterilizer  St  and  leaves 
by  the  valve  V.  The  air  enters  through  the  air  drier  Ad, 
goes  through  the  ozonizer  Oz,  and  by  means  of  the  pump  Op 
is  forced  into  the  bottom  of  sterilizer  St. 

An  ordinary  generator  Dy  delivers  its  alternating  cur¬ 
rent  to  a  switchboard  Sw  from  whence  it  goes  to  the  step-up 
transformer  Tr  (earthed),  and  from  here  to  the  ozonizer 
apparatus  Oz  (earthed). 

Figures  12,  13,  14,  15,  and  16  are  from  photographs 
of  the  Nieuwersluis  plant. 

When  once  properly  started  the  plant  requires  hardly 
any  attention.  The  only  question  of  importance  is  the  deter¬ 
mination  of  the  amount  of  ozone  required  for  the  particular 
water  to  he  treated  (to  provide  a  sufficient  quantity  of 
ozone).  There  are  two  methods  for  determining  whether 
the  quantity  of  ozone  supplied  be  sufficient  or  not.  First,  by 
testing  the  surplus  of  ozone  at  the  outlet  of  tube  4;  by  iodine 
of  starch  paper.  Second,  by  the  sense  of  smell.  As  long  as 
there  is  ozone  left  it  is  certain  that  there  has  been  sufficient 
to  destroy  the  bacteria,  and  if  more  absolute  certainty  is 
desired,  there  is  still  another  way,  viz  :  determining  by  chemi¬ 
cal  means  the  quantity  of  soluble  organic  matter  oxidized. 
Experience,  however,  is  a  safe  guide,  and  there  is  no  special 
skill  required  at  Nieuwersluis  to  run  the  plant.  Any  engi¬ 
neer  of  ordinary  intelligence  can  do  so. 

The  claims  made  for  the  high  efficiency  of  sand  filtra¬ 
tion  and  especially  slow  sand  filtration,  may  not  be  challenged 
in  the  face  of  the  magnificent  results  obtained  both  in  this 
country  and  in  Europe,  for  it  must  surely  be  conceded  that 
a  reduction  by  slow  sand  filtration  of  over  98%  in  the 
number  of  bacteria  present  in  the  raw  water  before  filtra¬ 
tion  is  a  splendid  showing,  and  the  remarkable  reduction  in 
the  number  of  typhoid  fever  cases,  wherever  sand  filtration 
has  been  introduced,  speaks  volumes.  Scientists,  however, 


Fig.  12.  The  Standpipe 


68 


will  not  be  satisfied  with  the  words,  “reduction  of,”  but  in¬ 
stead  insist  upon  total  elimination.  It  is  unnecessary  to  dwell 
on  the  material  loss  involved  in  the  appalling  annual  death 
rate  from  typhoid  fever  and  other  diseases  traceable  to  im¬ 
pure  water,  the  grief  and  misery  consequent  thereon  alone 
appealing  to  every  human  heart. 

That  the  biologic  action  of  any  filter  system,  per  sc,  is 
not  continuous  and  uniform  in  efficiency,  none  can  deny,  and 
that  in  any  filter  system  it  is  a  question  of  reduction  in  num¬ 
ber  of  cases  and  not  of  complete  cessation,  is  also  a  matter  of 
common  knowledge,  and  again,  clarification  with  partial 
purification,  and  clarification  with  total  purification  are  two 
different  things. 

It  must  he  admitted  that  by  boiling  the  water  after  filtra¬ 
tion  sterilization  is  produced  and  all  danger  from  pathogenic 
germs  avoided,  hut,  then,  it  must  be  apparent  that  if  boiling 
is  necessary  after  filtration,  the  filtration  may  he  accomplished 
by  what  is  called  rough  filtration  only ;  and  further,  the  means 
required  for  the  boiling  act  are  not  always  readily  at  hand, 
and  it  is  well  known  that  danger  signals  do  not  always 
prevail. 

The  following  article  is  from  the  London,  England, 
Evening  Standard,  of  March  2,  1904: 

Water  Filtering. 

“T11  very  few  directions  has  recent  science  revealed  any¬ 
thing  more  curious  and  interesting  than  in  that  which  has  to 
do  with  the  purification  of  water,  of  which  Londoners  have, 
in  one  way  or  another,  been  hearing  a  good  deal  more  than 
has  always  been  pleasant.  Singularly  enough,  although  the 
eight  London  Water  Companies  have  long  been  filtering 
river  water  on  a  vast  scale,  and,  it  may  be  presumed,  have  for 
many  years  been  closely  studying  the  subject,  the  latest 
advances  in  the  science  of  filtration  appear  to  have  resulted, 
not  from  any  experiments  with  the  comparatively  pure  water 
of  the  open  river,  hut  from  the  necessity  of  purifying  the 


Fig.  13.  Standpipe  and  Ozonized  Water  Basin 


70 


effluent  from  London  sewage.  There  have  been  three  clearly 
distinct  stages  in  the  science  of  filtration,  and  two  out  of  three 
are  quite  modern,  indeed  the  last  of  them  may  be  said  to 
have  been  only  quite  recently  attained.  When  the  first  of 
these  three  stages  was  arrived  at  the  world  must  have  been 
much  younger  than  it  is  now.  It  must  always  have  been 
obvious  enough  that  water  containing  any  kind  of  foreign 
matter,  such  as  fallen  leaves,  must  necessarily  have  it  elimi¬ 
nated  by  passing  through  a  bed  of  gravel  or  small  stones.  It 
is,  of  course,  a  mere  straining  process,  and  must  have  been 
recognized  as  a  means  of  purifying  water  almost  as  soon  as 
men  were  capable  of  discerning  the  difference  between  clean 
and  dirty  fluid.  But  though  the  mere  straining  of  water 
must  have  been  known  to  be  a  means  of  purifying  it  in  the 
very  early  days  of  civilization,  it  was  only  within  living 
memory  that  the  second  stage  in  the  science  of  the  thing  was 
attained.  For  untold  ages  it  was  supposed  that  the  filtration 
of  water  was  a  process  of  mere  mechanical  straining,  and  the 
London  filter  beds,  about  the  efficiency  of  which  so  much  has 
lately  been  said  before  the  Board  of  Arbitration  and  else¬ 
where,  were  all  originally  laid  down  on  this  rudimentary 
theory.  Many  middle-aged  Londoners  will  very  well  remem¬ 
ber  the  outcry  which  led  to  a  totally  new  theory  on  the 
subject.  The  Thames  at  Westminster  was  in  such  a  foul 
condition  that  the  windows  of  the  House  of  Commons  had 
to  be  kept  closed  because  of  the  stench.  At  the  same  time, 
only  a  little  higher  up  the  river,  water  was  being  drawn  off 
for  the  household  supply  of  Londoners.  There  was  an  out¬ 
cry  that  led  to  close  investigation.  Experts  were  employed 
to  analyze  the  water  in  the  river  and  the  water  in  the  Com¬ 
panies'  mains  after  passing  through  the  filters,  so  as  to  see 
what  had  been  actually  eliminated.  The  next  thing  was  to 
examine  the  intercepted  matter  left  in  the  filter  beds,  and 
then  a  very  curious  fact  came  out.  As  it  was  only  a  process 
of  straining  out  impure  matter  from  the  river  water,  it  was 
to  be  assumed  that  all  the  extracted  impurity  would  be  found 


Fig.  14.  The  Ozonizer 


ill  the  strainer.  But,  as  a  matter  of  fact,  it  was  not  all  found 
in  the  strainer.  A  very  large  part  of  it  had  totally  disap¬ 
peared.  What  had  become  of  it?  The  endeavor  to  answer 
this  question  soon  made  it  apparent  that  the  efficient  filtration 
of  water  depended  not  only  on  the  mere  straining  powers  of 
the  filter  but  on  a  process  of  chemical  decomposition  also,  and 
that  the  efficiency  of  a  filter  depended  on  its  power  of  pro¬ 
moting  this  chemical  action,  as  well  as  upon  its  mere  mechani¬ 
cal  action. 

“This  was  an  entirely  new  idea,  and  scientists  were  soon 
able  to  explain  the  matter.  A  filter  bed,  as  constructed  by  the 
London  companies,  was  a  porous  mass  of  stony  particles — 
pebbles,  coarse  and  fine  gravel,  broken  shells,  sand,  and  so 
on— and  around  every  particle,  even  the  most  minute,  there 
clung  a  film  of  condensed  air.  In  passing  down  through  the 
bed  the  water  and  the  impurity  it  contained  were  brought  into 
close  contact  with  these  tiny  films  of  air,  and  the  consequence 
was  that  organic  impurity — all  sorts  of  animal  and  vegetable 
matter — was  oxidized.  That  is  to  say,  the  organic  impurity 
entered  into1  chemical  combination  with  the  oxygen  of  the  air 
— just  as  a  candle  does — and  was  burnt  up — just  as  a  candle 
is  burnt  up.  That,  of  course,  explained  the  mysterious  dis¬ 
appearance,  and  the  new  theory  of  filtration  was  permanently 
established.  The  aeration  of  water  is  in  fact  its  greatest 
purifier,  whether  the  aeration  is  effected  in  a  clean,  fresh 
filter-bed,  or  by  tossing  the  fluid  into  the  air  in  a  fountain 
spray,  or  by  tumbling  it  over  a  rocky  cascade.  However  im¬ 
pure  river  water  may  be  at  one  point  in  its  course,  and  what¬ 
ever  be  the  nature  of  its  impurity,  only  let  it  go  rippling 
through  the  open  air  and  foaming  over  rocks,  and  it  will 
gradually  lose  all  its  pollution.  But  the  investigations  that 
led  to  the  establishment  of  this  second  theory  of  filtration 
started  another  difficulty  which  the  aeration  idea  was  incap¬ 
able  of  explaining.  If  water-filtering  had  been  only  a  matter 
of  straining  and  aeration,  then  the  cleaner  and  fresher  the 
filter  bed,  the  better  it  would  have  done  its  work.  But  every- 


Fig.  15.  Air  Pump,  Generator,  etc 


74 


body  was  much  puzzled  to  bud  that  as  a  matter  of  fact  it  was 
not  so,  and  there  were  many  cases  in  which,  yielding  to  the 
urgent  remonstrance  of  the  Local  Government  Board,  the 
Water  Companies  had  cleared  out  their  dirty  beds  and  put  in 
others  clean  and  fresh,  only  to  find  that  the  clean  new  beds 
were  not  so  efficient  as  the  old  dirty  ones.  Besides  mechani¬ 
cal  interception  and  chemical  absorption,  there  was  clearly 
something  else  involved  in  the  operation. 

“Seventeen  years  ago  some  idea  of  the  truth  of  the 
matter  had  begun  to  dawn  as  a  result  of  the  work  of  Pasteur, 
Koch,  and  others,  and  Mr.  Didbin,  the  chemist  of  the  County 
Council  at  that  time,  very  clearly  expressed  his  belief  before 
the  Institute  of  Civil  Engineers  that,  in  addition  to  the  me¬ 
chanical  and  the  chemical,  there  was  a  biological  factor  in 
the  matter,  though  at  that  time  knowledge,  he  said,  was  not 
sufficiently  advanced  to1  permit  of  any  biological  theory  being 
put  to  practical  application.  What  seemed  pretty  certain 
seventeen  years  ago  was  that  bacteria  and  others  of  the 
lowest  forms  of  life  had  something  important  to  do  in  elim¬ 
inating  impurity  from  water,  and  as  time  went  on  and  Ameri¬ 
can  chemists  as  well  as  our  own  took  up  the  subject,  so  much 
was  found  in  support  of  the  new  science  that  ten  or  eleven 
years  ago  the  thing  was  put  to  practical  test  by  laying  down  a 
new  bed  specially  designed  to-  enable  microbes  to  show  what 
they  were  capable  of.  The  new  filter  was  not  intended  for 
the  purification  of  river  water,  but  of  sewage  water  running 
out  from  the  subsiding  tanks  in  connection  with  the  London 
main  drainage  system.  If  these  little  bacterial  philanthropists 
could  deal  with  this  effluent  water  their  cleverness  and  use¬ 
fulness  would  require  no  further  test.  As  a  matter  of  fact 
they  came  out  splendidly.  The  beds  were  composed  of  a 
certain  thickness  of  coke  breeze,  and  through  this  the  foul 
effluent  water  was  passed  in  gradually  increasing  volume. 
Gradually  the  bacteria  increased  in  number  and  in  the  same 
proportion  the  filter  beds  increased  in  efficiency.  The  result 
showed — what  is  always  so  satisfactory  to  have  shown — that 


75 


the  past  had  not  been  all  wrong,  blit  only  incomplete.  Prac¬ 
tice  and  theory  had  both  been  right  so  far  as  they  had  gone. 
A  well-made  filter  bed  did  act  mechanically,  as  it  had  been 
supposed  to  do,  and  it  did  act  chemically  also  ;  but  the  chemi¬ 
cal  action  required  to  be  promoted  and  assisted  by  the  efforts 
of  the  microbes,  and  it  became  apparent  that  the  reason  why  a 
new  filter  bed  did  not  filter  water  so  thoroughly  as  an  old  one 
was,  that  there  were  no  bacteria  to  assist  in  the  business. 
The  oxidation  of  decayed  animal  and  vegetable  matter,  it 
now  appears,  depends  under  certain  circumstances,  upon  two 
minute  forms  of  animal  life — one  of  them  requiring  an  abun¬ 
dant  supply  of  fresh  air,  the  other  finding  all  it  requires  for 
health  and  happiness  in  the  densest  filth  it  can  ’find,  and 
apparently  without  the  smallest  need  of  any  atmospheric  air 
at  all.  In  the  foulest  mass  of  putrefactive  corruption  it  will 
live  and  thrive,  and  will  break  down  highly  organized  animal 
and  vegetable  substances  into  simpler  forms  of  matter  cap¬ 
able  of  being  appropriated  by  the  fresh  air  microbes,  or  of 
entering  directly  into  combination  with  the  fresh  air  of  the 
filter-bed  or  the  water-fall.  Thus  filtration  was  first  of  all 
mechanical,  next  chemical,  and  has  now  become  to  a  large 
extent  a  factor  of  animal  life  and  activity.” 

Abstract  of  remarks  made  at  the  Sanitary  Conference  of 
the  Health  Officers  of  Connecticut,  at  New  Haven,  December 
17,  1903,  on  “The  Failures  and  Possibilities  of  Water  Fil¬ 
tration,"  by  Allen  Hazen,  M.Am.  Soc.  C.  E.,  from  Engineer¬ 
ing  News,  December  31,  1903  : 

“Most  of  the  filters  that  have  been  installed  in  this 
country  have  failed  at  times  more  or  less.  Some  of  them  have 
failed  habitually  and  disastrously.  With  others  the  failures 
have  been  occasional  and  slight,  and  some  have  not  failed  at 
all.  By  failing  I  mean  that  water  has  been  sent  out  from 
them  falling  considerably  short  of  the  standard  of  purity 
established  by  reasonably  well  constructed  and  operated  filt¬ 
ers.  This  definition  may  be  a  little  hard  on  some  of  the  older 
plants,  for  nearly  all  of  them  have  served  to  improve  materi- 


/6 


ally  the  quality  of  the  water  which  has  passed  them,  and  to 
this  extent  they  have  been  successful.  I  am  considering  the 
matter,  however,  from  the  standpoint  of  the  most  exacting- 
requirements  of  the  present  time,  and  from  this  standpoint 
these  plants  cannot  be  considered  as  entirely  successful. 
These  shortcomings  of  filters  have  been  widely  advertised, 
and  as  I  say,  have  greatly  limited  the  extension  of  a  most  use¬ 
ful  process.  Progress  is  often  made  by  a  study  of  failures, 
and  I  want  to  talk  to  you  to-day  about  the  reason  for  these 
failures ;  and  why,  as  I  believe,  the  fact  that  there  have  been 
failures  should  not  be  given  too  much  weight  in  considering 
the  application  of  the  process  to  new  problems. 

“Let  us  consider  briefly  what  the  causes  of  the  failures 
have  been.  They  can  all  be  divided  into  two'  classes,  namely, 
those  resulting  from  defective  construction,  and  those  result¬ 
ing  from  defective  operation. 

“Under  the  first  head  we  have,  first,  the  defective  results 
which  are  obtained  from  filters  of  old  designs.  There  are 
still  in  the  United  States  many  filters,  built  before  the  art  of 
water  purification  was  much  developed  in  this  country ;  and 
while  some  of  these  old  filters  were  of  surprisingly  good 
design,  considering  the  time  at  which  they  were  built,  and 
have  been  and  still  are  doing  good  service,  there  are  many 
others  defective  in  important  particulars,  and  so  far  failing 
to  represent  the  conditions  known  by  modern  experience  to  be 
essential  to  success  that  the  results  obtained  from  them  are 
very  inferior.  In  some  extreme  cases  the  water  is  hardly 
purified  at  all,  and  the  filtration  might  almost  as  well  be 
abandoned. 

“As  the  second  cause  I  will  mention  inadequate  con¬ 
struction.  By  this  I  mean  the  cases  where  filters  are  pro¬ 
vided  of  too  small  capacity  for  the  work  to  be  done,  or 
where,  in  order  to  save  money,  the  appliances  provided  are 
materially  below  those  demanded  by  standard  practice.  This 
has  been,  and  still  is  a  very  important  element  in  unsatis¬ 
factory  results  from  filters. 


77 


“As  a  third  cause  we  have  the  blind  copying  of  designs 
successfully  used  elsewhere.  There  have  been  many  failures 
in  American  biters  coming  under  this  class,  that  is,  by  inju¬ 
dicious  applications  of  good  designs. 

“As  the  last  head  under  defects  of  construction,  I  place 
experimental  construction ;  and  this  is  by  far  the  hardest  one 
in  the  series  to  guard  against  successfully. 

“Nearly  all  biter  designs  are  to  some  extent  experi¬ 
mental.  That  is  to  say,  it  is  still  impossible  to-  reproduce  a 
plant  and  all  the  conditions  under  which  it  operates  in 
another  locality.  There  is  always  something  new,  for  the 
general  practice  of  water  puribcation  has  reached  such  a  state 
that  for  very  large  range  of  waters,  a  range  so  wide  as  to 
include  most  of  the  waters  used  for  public  water  supplies  in 
the  United  States,  biters  can  be  selected  which  much  resemble 
biters  which  have  been  successfully  used  for  the  same  kind  of 
water  elsewhere  that  the  experimental  element  in  construc¬ 
tion  is  reduced  to  a  minimum. 

“If  all  experimental  construction  should  be  shut  out, 
the  art  of  water  puribcation  would  become  stereotyped,  and 
this  is  certainly  not  the  result  that  we  are  looking  for.  But, 
on  the  other  hand,  it  must  be  frankly  admitted  that  a  large 
part  of  the  failures  in  water  filtration  have  resulted  from 
experimental  construction. 

“The  conservative  and  rational  course  seems  to  be  to 
adopt  in  important  new  constructions  only  such  improve¬ 
ments  as  are  of  a  type  to  allow  of  very  complete  and  certain 
analysis ;  and  when  it  seems  advisable  to  make  other  and 
more  radical  changes,  the  effects  of  which  seem  promising, 
but  which  cannot  be  told  certainly  in  advance  of  trial,  they 
should  be  used  only  in  a  small  and  tentative  way,  or  they 
should  be  examined  by  experiment  made  for  that  purpose  in 
advance  of  actual  use. 

“When  cities  have  built  filters  founded  on  entirely  new 
processes,  differing  radically  from  the  lines  of  approved  prac¬ 
tice,  as  a  few  cities  in  this  country  have  done,  the  results  in 


73 


some  cases,  I  think  in  nearly  all  cases,  have  been  complete 
failures. 

“The  second  class  of  failures  are  those  due  to  defects  in 
operation.  Of  these  many  come  from  lack  of  proper  atten¬ 
tion.  The  filter  is  put  in  the  hands  of  some  one  who  does  not 
understand  it,  or  who  does  not  know  the  importance  of  main¬ 
taining  proper  operation,  and  it  is  neglected  at  some  time,  or 
even  habitually,  and  the  results  fall  off  in  consequence.  Some¬ 
times  the  failure  in  operation  comes  from  the  desire  to  econ¬ 
omize.  This  happens  most  frequently  in  those  filters  where 
chemicals  are  used  as  an  aid  to  purification  and  where  a  direct 
saving  can  be  made  by  using  amounts  of  coagulant  below 
the  amounts  necessary  for  the  best  efficiency. 

kT  hope  that  I  have  made  it  clear  to  you  that  these 
causes  of  failure  are  precisely  the  same  as  those  which  cause 
failure  in  any  undertaking  and  that  they  can  be  eliminated 
and  guarded  against  by  the  same  kind  of  precautions  that  are 
necessary  to  success  in  any  business. 

“The  risk  of  using  the  water  from  a  filter  plant  should 
be  as  little  as  the  risk  of  traveling  upon  a  train ;  in  fact,  it 
should  be  less,  for  the  opportunities  for  control  and  safe¬ 
guard  are  greater ;  and  it  can  be  arranged  so  that  the  chemist 
takes  sample  of  the  water  from  a  point  entirely  beyond  the 
control  of  those  in  charge  of  the  filters,  and  examine  such 
sample  so  frequently  as  to  enable  him  to  detect  any  failure  to 
accomplish  the  desired  results  from  any  cause  whatever;  and 
we  may  be  sure  that  the  man  at  the  filters  will  not  put  himself 
in  the  way  of  being  caught  napping  under  such  supervision. 

“Experience  demonstrates  that  this  can  be  accomplished. 
In  Europe  there  are  many  filter  plants  operated  on  this  basis. 
In  this  country  there  are  few.  From  these  plants  water  of  the 
very  best  quality  is  uninterruptedly  supplied  year  in  and  year 
out  without  a  break,  and  with  as  little  chance  of  failure  as 
there  is  in  the  use  of  almost  any  appliance  in  common  use. 
The  number  of  such  plants  is  increasing  and  will  increase, 
and  as  time  goes  on,  and  as  the  subject  is  better  understood, 


79 


and  is  understood  by  more  people,  the  plants  that  are  insuffi¬ 
cient  and  badly  designed,  and  inadequate  because  out  of 
date  will  be  gradually  replaced  by  better  ones ;  and  the  su¬ 
perintendents  and  foremen  who  are  not  faithful  and  careful 
will  be  superseded  by  better  educated  and  more  careful  men. 

“I  want  to  emphasize  to  you  to-day,  gentlemen,  that 
what  is  needed  in  water  purification  plants  is  not  so  much 
new  processes  and  better  processes  as  more  careful  and  intel¬ 
ligent  and  faithful  application  of  the  processes  that  we  now 
have. 

“The  efficiency  of  filtration  is  well  illustrated  by  the 
history  of  the  water  supplies  of  Paris  and  its  suburbs  in  the 
last  two  decades.  Paris  has  long  had  a  supply  of  spring 
water,  brought  through  aqueducts  from  distant  sources — - 
aqueducts  comparable  in  their  size  and  cost  to  those  won¬ 
derful  aqueducts  which  supplied  ancient  Rome.  The  quality 
of  this  spring  water  was  regarded  to  be  the  very  best.  The 
unfortunate  feature  of  the  situation  was  that  there  was  not 
enough  spring  water  for  all,  and  it  was  necessary  to  supple¬ 
ment  the  supply  at  times  by  pumping  river  water  into  the 
pipes.  Typhoid  fever  was  prevalent  in  Paris  and  was 
believed  to  be  due  to  this  mixture  of  river  water. 

“In  1830  Paris  completed  a  new  aqueduct,  bringing  in 
some  entirely  new  springs  of  large  capacity  and  for  the  first 
time  in  a  good  many  years  there  was  enoug'h  spring  water, 
and  it  was  no  longer  necessary  to  pump  river  water  into  the 
pipes  for  domestic  use.  After  this  the  typhoid  fever  rate  in 
Paris  decreased  very  rapidly.  When  Paris  grew  beyond  its 
bounds,  and  suburbs  developed  with  a  population  of  several 
hundred  thousand,  these  suburbs  were  not  annexed  because 
there  was  not  enough  spring  water  to  go  around ;  and  Paris 
was  unwilling  to>  divide  with  them.  These  suburbs  were  en¬ 
tirely  unable  to  secure  a  supply  of  spring  water  of  their  own. 
The  next  best  thing  available  to  them  was  to  use  the  river 
water  with  filtration,  and  filters  were  established  at  several 
points  by  the  company  supplying  them ;  and  these  filters 


were  put  in  operation  at  about  the  same  time  that  Paris 
secured  sufficient  spring  water. 

“There  were  then  these  two  bodies  of  population ;  Paris 
the  inner  city,  supplied  entirely  with  spring  water,  and  the 
ring  of  suburbs  outside  supplied  by  filtered  river  water;  and 
it  was  soon  noticed  that  typhoid  fever  was  much  less  preva¬ 
lent  in  the  suburbs  than  it  was  in  the  city.  Thus  when  the 
two  kinds  of  supplies  were  put  to  the  ultimate  test  the  filtered 
river  water  proved  better  than  the  spring  water.  For  the 
last  few  years  a  commission  composed  of  many  of  the  lead¬ 
ing  scientists  and  engineers  of  Paris  have  been  considering 
this  question,  and  it  has  found  pollutions  entering  the  springs 
so  numerous  and  so  great  as  to  amply  explain  the  higher 
death  rate  among  the  users  of  this  water.  It  has  been  pos¬ 
sible  to  shut  off  some  of  these  sources  of  pollution,  and 
some  of  the  springs  have  been  excluded  and  filters  have  been 
built  to  make  up  the  deficiency  with  filtered  river  water,  and 
the  conditions  are  thus  improved,  but  the  matter  of  entirely 
correcting  them  is  difficult.  It  has  been  proposed  to  filter  the 
spring  water  supplies,  and  other  and  new  sources  are  under 
consideration,  but  no  decision  has  been  reached  as  yet. 

“At  the  present  time  there  seems  to  be  a  source  of  arbi¬ 
trary  standard  in  the  methods  of  water  purification.  That  is 
to  say,  methods  are  extensively  used  which  make  the  cost  of 
purifying  a  million  gallons  of  water,  including  interest  and 
sinking  fund  charges,  somewhere  in  the  neighborhood  of  $10, 
and  which  are  sufficient  to  remove  99  or  99F2  %  of  the 
bacteria  of  the  applied  water.  This  may  fairly  be  called  the 
best  practice  to-day.  A  purification  like  this  serves  to  furnish 
a  water  from  the  Merrimac,  or  from  the  Hudson,  in  every 
respect  as  good,  and  perhaps  better  than  is  obtained  from  the 
best  upland  sources.  It  would  be  difficult  to-  produce  suffi¬ 
cient  reasons  and  to  back  them  up,  to  induce  a  water  board 
or  City  Council  to  authorize  the  necessary  expenditure  to 
produce  a  much  more  complete  purification  than  this,  but  it  is 
important  to  keep  this  matter  in  sight,  and  to  note  that,  if 


8 1 


the  pollution  of  our  rivers  increases,  the  purification  can  be 
made  to  keep  pace  with  this  increase,  and  it  will  be  possible 
to  obtain  water  of  the  best  equality,  even  though  conditions 
become  far  less  favorable  than  they  are  to-day. 

“The  triumphs  in  the  past  have  been  great.  The  typhoid 
fever  death  rates  in  a  number  of  cities  have  been  reduced  by 
the  installation  of  filters  by  70%  or  80%  or  more.  General 
death  rates  have  also  been  reduced  by  amounts  which  cor¬ 
respond  to  much  more  than  the  reduction  in  the  typhoid  fever 
rates.  Perhaps  the  achievements  of  the  future  in  this  respect 
will  not  he  more  striking  than  those  in  the  past,  but  this  cer¬ 
tainly  is  true,  that  with  the  gradual  raising  of  the  standards 
of  the  quality  of  water  supplies,  and  with  the  growth  of  a 
desire  for  cleaner  and  purer  water,  the  art  of  water  purifi¬ 
cation  will  advance  and  its  application  will  be  constantly  ex¬ 
tended,  with  the  greatest  benefit  to  the  people  of  our  cities.” 

Some  Lessons  of  the  Butler  Typhoid  Epidemic. 

From  Engineering  Neivs,  December  31,  1903. 

“Hard  as  it  is  upon  fever  stricken  Butler,  the  typhoid 
epidemic  in  that  community  may  be  the  means  of  saving  thou¬ 
sands  of  lives  elsewhere  by  directing  public  attention  to  the 
dangers  of  polluted  water  and  inefficient  sanitary  administra¬ 
tion. 

“We  say  thousands  of  lives  advisedly  and  with  full 
knowledge  that  the  total  number  of  deaths  in  such  epidemics 
as  that  of  Butler  or  at  Ithaca  fall  far  short  of  any  such  num¬ 
ber.  The  fact  is  that  the  great  mortality  from  typhoid  fever 
results  from  the  numerous  cases  which  are  occurring  all  the 
time  in  all  parts  of  the  country  without  the  disease  becoming 
sufficiently  prevalent  to  be  called  epidemic. 

“In  the  past  twenty  years  there  have  been  only  two 
typhoid  epidemics  comparable  with  that  of  Butler,  viz  :  Plym¬ 
outh,  Pa.,  in  1885,  and  Ithaca,  N.  Y.,  a  few  months  ago. 
The  total  number  of  recorded  typhoid  cases  in  these  three 
epidemics  will  probably  be  somewhere  near  3500  to  4000  and 


82 


the  recorded  deaths  three  hundred  or  more.  Meanwhile  not 
a  year  has  gone  by  when  thousands  upon  thousands  of  per¬ 
sons  have  not  been  stricken  and  many  thousands  died  on 
account  of  the  pollution  of  the  public  water  supplies  of  the 
United  States.  In  other  words,  the  great  water-borne 
typhoid  epidemics  have  been  few  and  at  long*  intervals,  but 
there  are  numerous  cities  with  polluted  water  supplies  in 
which  typhoid  is  always  prevalent.  Thus  it  is  not  merely 
to  avert  the  danger  of  epidemics  that  thousands  of  American 
communities  need  radically  to  reform  their  sanitary  con¬ 
ditions.  Such  action  is  needed  to  eliminate  the  cases  of 
typhoid  which  occur  every  year  and  often  at  all  times  of  the 
year.  What  at  first  thought  may  seem  to  be  a  sweeping  con¬ 
demnation  of  private  ownership  of  water  works  is  a  fact  that 
the  three  great  typhoid  epidemics  at  Butler,  Ithaca  and  Plym¬ 
outh  were  all  caused  by  water  supplied  by  private  companies. 
But  on  the  other  hand,  what  shall  be  said  of  tbe  equally 
striking  fact  that  municipal-owned  waterworks  head  the 
list  of  cities  with  continuously  high  typhoid  mortality?  For 
the  years  1898  to  1901,  the  City  of  Pittsburg,  most  of  whose 
population  is  supplied  with  water  from  city  works,  had  an 
average  typhoid  mortality  of  1 1 3  per  100,000,  standing  at 
the  top  of  the  list  of  cities  of  thirty  thousand  and  upwards. 
Charleston,  S.  C,  under  private  ownership,  came  next 
(no),  but  was  followed  by  three  cities  owning  their  works, 
namely:  Youngstown,  O. ;  Allegheny,  Pa.;  and  Troy,  N.  Y. 
( 109,  90  and  90  respectively).  It  would  be  interesting,  and 
perhaps  profitable,  to  go  all  through  the  list  and  see  how  the 
ownership  stands  as  the  typhoid  mortality  lowers,  but  our 
present  space  and  purpose  will  not  permit  such  an  analysis. 
While  there  is  reason  to  believe  that  a  pure  water  supply  can 
be  more  readily  secured  and  maintained  under  municipal 
ownership,  it  is  at  the  same  time  true  that  polluted  water 
is  now  being  furnished  by  hundreds  of  waterworks,  includ¬ 
ing  which  are  very  many  works  owned  by  cities  as  well  as 
those  owned  by  private  companies. 


“Even  in  cities  where  radical  changes  in  the  waterworks 
are  not  needed,  there  is  frequently  urgent  need  for  a  thorough 
sanitary  study  of  the  water  supply,  to  be  followed  by  constant 
sanitary  supervision,  all  under  the  direction  of  technically 
trained  men. 

“To  inaugurate  such  sanitary  reforms  there  is  needed 
not  only  action  by  the  towns  and  cities  but  by  State  authori¬ 
ties.  It  is  not  difficult  to  trace  a  direct  connection  between  the 
epidemic  at  Butler  and  the  fact  that  Butler  is  located  in  the 
State  of  Pennsylvania.  That  State,  to  put  matters  plainly,  is 
well  known  among  sanitarians  to  be  notably  backward  in  all 
matters  concerning  the  protection  of  the  public  health.  This 
is  not  a  mere  matter  of  opinion.  It  can  be  shown  by  statistics 
which  represent  human  lives. 

“In  order  to  show  by  concrete  example  what  sanitary 
neglect  in  Pennsylvania  really  means,  let  us  compare  the 
records  of  typhoid  fever  mortality  in  its  cities  with  those  of 
cities  in  Massachusetts,  a  State  much  more  densely  populated, 
but  well  known  the  world  over  for  its  advanced  position  in 
matters  of  sanitation.  Among  the  cities  of  the  United  States 
having  30,000  population  and  over  for  which  typhoid  mor¬ 
tality  statistics  for  the  four  years  1898  to  1901  are  available, 
Pennsylvania  has  15  and  Massachusetts  has  17  cities.  Nearly 
all  the  Pennsylvania  cities  are  among  those  of  high  mortality 
and  every  one  of  the  Massachusetts  cities  is  among  those 
having  low  typhoid  death  rates.  The  total  range  of  the  table, 
it  may  be  added,  is  from  the  very  high  rate  of  1 13  to  the  low 
rate  of  6  deaths  per  hundred  thousand  of  population  per 
annum. 

“Pittsburg  heads  the  table  with  113  typhoid  deaths  per 
annum,  and  Allegheny  comes  fourth  with  90.  Johnstown 
stands  six  and  York  ninth,  making  four  Pennsylvania  cities 
among  the  first  ten.  The  four  Pennsylvania  cities  in  the  last 
half  of  the  table  stand  number  67,  75,  94  and  95,  the  last  two 
being  Erie  and  Scranton,  each  with  an  average  typhoid  mor¬ 
tality  of  25  per  100,000. 


84 


“In  Massachusetts,  New  Bedford  shows  an  average 
mortality  of  30  per  100,000,  Boston  and  Springfield  show¬ 
ing  an  average  mortality  of  26  per  100,000. 

“To  what  shall  the  vastly  superior  showing  of  the  Mas¬ 
sachusetts  cities  be  ascribed?  The  records  of  the  past  show 
that  it  is  due  almost  wholly  to  the  relatively  high  character 
of  the  water  supplies  and  to  efficient  sanitary  administration. 

“Several  years  ago  a  number  of  Massachusetts  cities 
were  notorious  for  their  high  typhoid  death  rates ;  but  the 
work  of  the  State  and  local  Boards  of  Health,  backed  by 
sound  public  opinion,  has  largely  remedied  former  evils  and 
has  made  the  State  foremost  the  world  over  for  its  efficient 
sanitation.  The  work  of  the  Massachusetts  State  Board  of 
Health  in  lessening  water  pollution  and  solving  the  problem 
of  sewage  and  water  purification  has  been  recognized  by  the 
sanitary  experts  of  all  civilized  nations  as  one  of  the  most 
notable  advances  in  public  sanitation  ever  recorded. 

“Contrast  with  this  record  the  record  of  Pennsylvania. 
Among  sanitarians,  foreign  and  American,  the  State  is  chiefly 
notable  as  an  example  of  the  results  of  sanitary  neglect. 

“For  decades  the  great  city  of  Philadelphia  has  had  to 
drink  the  foul  waters  of  the  Schuylkill  and  Delaware,  and 
thousands  of  lives  have  been  thereby  sacrificed.  Only  now, 
after  a  generation  of  agitation  and  delay,  has  the  city  en¬ 
tered  upon  the  construction  of  filtration  plants  to  purify  its 
water  supplies. 

“Pittsburg,  which,  as  we  have  stated  above,  has  long- 
been  notorious  for  its  high  typhoid  rate  and  is  now  suffering 
to  an  extent  which  almost  assumes  the  proportions  of  an 
epidemic,  deserves  credit  for  having  a  few  years  ago  ex¬ 
pended  a  large  sum  of  money  in  water  purification  experi¬ 
ments.  It  deserves  nothing  but  discredit,  however,  for 
ignoring  these  experiments  and  delaying  the  work  of  water 
purification.  Its  citizens  suffer  and  die  by  the  hundred,  while 
rival  politicians  and  contractors  struggle  for  party  advantage 


85 

and  personal  gain  in  connection  with  the  proposed  construc¬ 
tion  of  filtration  works. 

“ Allegheny,  so  far  as  we  can  learn,  also  continues  to 
pay  a  heavy  penalty  for  impure  water,  notwithstanding  the 
huge  filter  crib  at  its  Allegheny  River  intake,  which  it  con¬ 
structed  at  great  expense  a  few  years  ago. 

‘‘Reading,  standing  No.  33,  or  just  below  Philadel¬ 
phia,  in  the  list  of  cities  already  reviewed,  is  making  some 
progress  towards  the  introduction  of  filters,  but  its  past 
record  is  not  one  to  be  proud  of.  At  Chester  the  water  com¬ 
pany  has  installed  filters,  but  it  appears  to  have  been  driven 
to  do  it  by  litigation. 

“It  would  be  interesting  to  inquire  to  what  extent  the 
backward  sanitary  condition  of  Pennsylvania  is  due  to  its 
local  municipal  government  or  to  its  State  government.  Un¬ 
doubtedly  both  are  deserving  of  extreme  censure.  The  State 
Legislature  has  not  been  liberal  in  its  appropriation  for  the 
State  Board  of  Plealth,  nor  has  it  clothed  that  body  with 
the  powers  which  it  needs  to  carry  on  a  fight  against  water 
pollution.  Moreover,  unless  by  quite  recent  legislation, 
needed  powers  for  the  conservation  of  the  purity  of  public 
water  supplies  has  not  been  granted  to  either  local  authorities 
or  water  companies.  With  such  a  record  is  it  any  wonder 
that  Pennsylvania  has  to  its  debit  two  of  the  three  great 
typhoid  epidemics  which  have  occurred  in  this  country  or 
that  most  of  its  large  cities  have  for  years  reported  heavy 
mortality  from  typhoid? 

“It  may  be  said  in  defense  of  Pennsylvania,  perhaps, 
that  her  sanitary  condition  is  no  worse  than  that  of  the  States 
which  have  not  been  named  and  that  a  comparison  with  Mas¬ 
sachusetts,  noted  the  world  over  for  its  sanitary  achievement 
and  its  excellent  State  and  local  government,  is  unfair.  Even 
if  such  a  plea  could  be  supported  by  facts,  which  is  doubtful, 
is  it  a  worthy  defense? 

“Pennsylvania  as  a  State  is  wealthy  and  prosperous;  it 
can  afford  to  better  its  sanitary  condition.  The  cities  which 


86 


have  grown  up  within  its  borders  entail  a  responsibility  that 
may  not  be  likely  ignored.  Sanitary  conditions  inherited 
from  primitive  days  become  unbearable  as  population  grows 
more  dense  and  as  means  for  the  spread  of  communicable 
disease  are  multiplied. 

“It  is,  therefore,  no  defense  for  Pennsylvania  to  cite  the 
backward  sanitary  condition  of  States  farther  East  or  farther 
West.  The  State  is  rich  enough  to  afford  good  sanitation 
and  its  densely  populated  cities  demand  such  sanitation  as  the 
price  of  their  citizens'  lives.  It  is  to  be  hoped  that  such  object 
lessons  as  the  calamity  at  Butler  may  have  an  influence 
towards  bringing  about  reform." 

On  page  166  of  the  Municipal  Journal  and  Engineer , 
Vol.  XVI,  No.  4,  April,  1904,  appears  an  article  entitled 
“Purification  of  Water  by  Ozone:  A  Chemical  Process 
Requiring'  no  After  Treatment — Frees  Water  from  Bacteria 
and  Iron — How  it  is  Done."  In  this  article  Dr.  Erlwein,  of 
Berlin,  speaking  on  this  subject  at  the  forty-third  annual 
meeting  of  the  German  Union  of  Gas  and  Water  Engineers, 
and  describing  the  ozonizing  apparatus  in  use  for  the  purifi¬ 
cation  of  the  water  supply  of  Paderborn,  in  Germany,  refer¬ 
ring  to  the  ozonizing  plant  at  Martinikenfeld,  says:  “It  has 
been  thoroughly  tested  with  Spree  water  full  of  cholera, 
typhus  and  other  disease  germs  artificially  reared  and  added 
to  the  water.  The  result  was  to  prove  that  the  ozone  treat¬ 
ment  killed  all  the  disease  germs  even  when  in  greater  num¬ 
bers  than  are  present  during  epidemics. 

“As  regards  the  chemical  effect  of  the  ozonization  of 
water  it  diminishes  the  oxidization  degree  of  the  water  by 
fifteen  to  twenty-five  per  cent,  and  increases  its  content  of 
free  oxygen.  The  ozone  reaction  vanishes  a  few  seconds 
after  the  water  leaves  the  tower,  and  no  taste  is  given  to  the 
water  *  *  *.  Ozone  is  not  only  a  bactericide  but  frees 

water  so  perfectly  from  iron  that  it  may  well  be  used  for  that 
purpose  alone  *  *  *.  The  ozonization  process,  too, 

should  not  cause  forgetfulness  of  the  immense  service  which 


the  sand  filtration  of  water  has  rendered  to  sanitation,  in 
spite  of  the  unquestionable  efficacy  of  ozonization  in  killing 
all  pathogenic  bacteria,  while  sand  filtration  does  nothing- 
more  than  diminish  their  number.  The  ozone  process  must 
always  be  taken  seriously  into  consideration  where  difficulties 
arise  in  large  towns  as  regards  extending  already  existing 
filter  beds  or  making  new  ones,  when  they  may  need  the  ac¬ 
quisition  of  land  at  heavy  expense.  The  ozone  plant  is  also 
excellent  for  places  where  it  is  impossible  to  rely  too  much 
on  the  waterworks  staff.  *  *  *. 

“*  *  *  There  are  cases,  too,  in  which  iron  and 

organisms  giving  taste  and  smell  to  the  water  can  only  be 
removed  by  ozone.  In  short,  every  case  must  be  judged  in¬ 
dependently  for  the  determination  of  the  most  suitable  sys¬ 
tem,  or  combination  of  systems,  for  purifying  the  water.” 

I  think  it  is  safe  to  say  that  the  various  authorities  which 
the  writer  has  quoted,  and  which  authorities,  both  European 
and  American,  are  conceded  to  rank  among  the  highest,  bear 
witness  to  the  following  facts : 

First. — ' That  filtration  alone  can  in  addition  to  clarify¬ 
ing  water  effect  purification  of  the  same,  only  to  a  degree 
varying  with  construction,  maintenance,  supervision,  etc., 
of  the  plant,  and 

Second. — That  by  ozonizing  a  previously  clarified  water 
absolute  purity  is  obtained.  Hence  I  cannot  but  express 
the  belief  that  as  an  adjunct  to  any  filtration  system, 
sufficiently  efficient  to  produce  clear  water,  sterilization  by 
ozone  will  prove  to  be  one  of  the  greatest  blessings  of  this 
century. 


(Signed)  J.  J.  de  Kinder. 


II  III  Hill  I  II  II II  III 


